# IELTS vocabulary list 258 academic words from IELTS Reading passages, each with a meaning, a CEFR level and a sentence from a passage. - **curriculum** /kəˈrɪkjələm/ (noun, B2): the subjects and content taught in a school or course. _Besides approving textbooks, Monbusho also decides the highly centralised national curriculum and how it is to be delivered._ - **literacy** /ˈlɪtərəsi/ (noun, B2): the ability to read and write. _For three students, even these literacy demands are beyond them._ - **assess** /əˈses/ (verb, B2): to judge the nature, quality or value of something. _"The way telecoms salespeople work is through personal and frequent contact with clients, using the benefit of experience to assess a situation and reach a decision._ - **attainment** /əˈteɪnmənt/ (noun, C1): the level of success reached, especially in school. _Japan has a significantly better record in terms of average mathematical attainment than England and Wales._ - **cognitive** /ˈkɒɡnətɪv/ (adjective, C1): connected with thinking, learning and understanding. _The concept of intelligence as something innate has been supplanted by the idea that intelligence is not fixed, and that, with the right training, we can be the authors of our own cognitive capabilities._ - **comprehension** /ˌkɒmprɪˈhenʃn/ (noun, B2): the ability to understand something, especially text. _Multiple studies show that digital screen use may be causing a variety of troubling downstream effects on reading comprehension in older high school and college students._ - **gifted** /ˈɡɪftɪd/ (adjective, B2): having a natural ability or talent. _"We didn't find anything other than playing chess that he seems to be supremely gifted at."_ - **undergraduate** /ˌʌndəˈɡrædʒuət/ (noun, B2): a university student studying for a first degree. _Any undergraduates who have met the academic requirements can sign up for the course in our program in "fire science"._ - **bilingual** /ˌbaɪˈlɪŋɡwəl/ (adjective, B2): able to speak two languages well. _According to the latest figures, the majority of the world's population is now bilingual or multilingual, having grown up speaking two or more languages._ - **fluent** /ˈfluːənt/ (adjective, B2): able to speak a language easily and well. _With dwindling numbers of Gomera islanders still fluent in the language, Canaries' authorities are taking steps to try to ensure its survival._ - **peer** /pɪə/ (noun, B2): a person of the same age, level or status as you. _While teachers are traditionally the MKOs in classrooms, the value of knowledgeable student peers must not go unrecognised either._ - **sustainable** /səˈsteɪnəbl/ (adjective, B2): able to continue without harming the environment. _Many scholars think that the compact city, built upwards instead of outwards, integrated with nature (especially water systems), with efficient transport infrastructure, could help modern cities become more efficient and sustainable._ - **emission** /iˈmɪʃn/ (noun, B2): gas or other substance sent out into the air. _Concrete is the second most used substance in the global economy, after water - and one of the world's biggest single sources of greenhouse gas emissions._ - **ecosystem** /ˈiːkəʊsɪstəm/ (noun, B2): all the living things in an area and how they interact. _These are complex ecosystems, rich in unique plant and animal life._ - **habitat** /ˈhæbɪtæt/ (noun, B2): the natural home of an animal or plant. _Another threat to the survival of the saiga is loss of habitat, as a result of agricultural expansion and human settlement._ - **biodiversity** /ˌbaɪəʊdaɪˈvɜːsəti/ (noun, C1): the variety of plants and animals in an area. _"We're seeing huge peatland forests with extremely high biodiversity value being lost for a few decades of oil palm revenues," says Silvius._ - **conservation** /ˌkɒnsəˈveɪʃn/ (noun, B2): protecting animals, plants and natural places from harm. _"However, we also want to highlight the research and conservation efforts that are now being carried out to try to save them from the threat of global warming."_ - **extinction** /ɪkˈstɪŋkʃn/ (noun, B2): the end of a species, when none are left alive. _It was almost driven to extinction by hunters in the 19th century._ - **endangered** /ɪnˈdeɪndʒəd/ (adjective, B2): at risk of dying out completely. _All three manatee species are endangered or at a heightened risk of extinction._ - **deforestation** /ˌdiːˌfɒrɪˈsteɪʃn/ (noun, B2): cutting down large areas of trees. _More specifically, he's interested in how bats are responding to human activity and deforestation in particular._ - **erosion** /ɪˈrəʊʒn/ (noun, B2): gradual wearing away of soil or rock by water or wind. _Cutting down native woodland leads to erosion, as there is nothing to keep the soil in place._ - **drought** /draʊt/ (noun, B2): a long period with little or no rain. _He believes the huarango was key to the ancient people's diet and, because it could reach deep water sources, it allowed local people to withstand years of drought when their other crops failed._ - **renewable** /rɪˈnjuːəbl/ (adjective, B2): (of energy) coming from sources that are not used up. _Angel says that his plan is "no substitute for developing renewable energy: the only permanent solution"._ - **greenhouse** /ˈɡriːnhaʊs/ (adjective, B2): (of gases) trapping heat in the earth's atmosphere. _In 1998, energy consumption in the transport sector was to blame for 28% of emissions of CO₂, the leading greenhouse gas._ - **pollutant** /pəˈluːtənt/ (noun, C1): a substance that makes air, water or land dirty. _The condition appears to result from the cumulative effect of a number of factors, with atmospheric pollutants the principal culprits._ - **degradation** /ˌdeɡrəˈdeɪʃn/ (noun, C1): the process of becoming worse in condition or quality. _Peter Groffman, from the Cary Institute of Ecosystem Studies in New York, points out that soil scientists have been warning about the degradation of the world's soil for decades._ - **deplete** /dɪˈpliːt/ (verb, C1): to reduce something so much that little is left. _A great deal of habitat was lost through forest clearance, and introduced species such as deer depleted the remaining forests of food._ - **species** /ˈspiːʃiːz/ (noun, B2): a group of animals or plants of the same kind. _The saiga, a species of antelope native to Central Asia, once roamed the vast grasslands of this region in enormous herds, many millions strong._ - **predator** /ˈpredətə/ (noun, B2): an animal that hunts and eats other animals. _The female kākāpō has to spend long periods away from the nest searching for food, which leaves the unattended eggs and chicks particularly vulnerable to predators._ - **climatic** /klaɪˈmætɪk/ (adjective, C1): relating to weather conditions over a long period. _Petrie believes that archaeologists are in a unique position to investigate how past societies responded to environmental and climatic change._ - **pesticide** /ˈpestɪsaɪd/ (noun, B2): a chemical used to kill insects that damage crops. _Apart from engendering widespread ecological disorders, pesticides have contributed to the emergence of a new breed of chemical-resistant, highly lethal superbugs._ - **fertiliser** /ˈfɜːtəlaɪzə/ (noun, B2): a substance added to soil to help plants grow. _Farmers have been putting this synthetic fertiliser on their fields ever since._ - **irrigation** /ˌɪrɪˈɡeɪʃn/ (noun, C1): supplying water to crops through channels or pipes. _Unprecedented construction of tens of thousands of monumental engineering projects designed to control floods, protect clean water supplies, and provide water for irrigation and hydropower brought great benefits to hundreds of millions of people._ - **reintroduce** /ˌriːɪntrəˈdjuːs/ (verb, C1): to bring an animal or plant back to an area. _The attempt to reintroduce this predator marries well with the aim of bringing forests back to parts of our bare and barren uplands._ - **mitigate** /ˈmɪtɪɡeɪt/ (verb, C1): to make something harmful less serious. _This grass growth would reduce temperatures, and mitigate emissions from melting permafrost._ - **artificial** /ˌɑːtɪˈfɪʃl/ (adjective, B2): made by people rather than existing naturally. _Conservationists have put the final touches to a giant artificial reef they have been assembling at the world-renowned Zoological Society of London (London Zoo)._ - **automation** /ˌɔːtəˈmeɪʃn/ (noun, C1): using machines or computers to do work people did. _The automotive sector is well used to adapting to automation in manufacturing._ - **automated** /ˈɔːtəmeɪtɪd/ (adjective, B2): operated by machines or computers instead of people. _If a significant proportion of the population choose to use shared automated vehicles, mobility demand can be met by far fewer vehicles._ - **algorithm** /ˈælɡərɪðəm/ (noun, C1): a set of rules a computer follows to solve a problem. _This is the philosophy that, given enough data, machine learning algorithms can solve all of humanity's problems._ - **innovation** /ˌɪnəˈveɪʃn/ (noun, B2): a new idea, method or product. _Birdseye was responsible for several key innovations that made the frozen food industry possible._ - **sensor** /ˈsensə/ (noun, B2): a device that detects heat, light, movement or sound. _In 2006, they teamed up with technology company Apple to launch Nike+, a digital sports kit comprising a sensor that attaches to the running shoe and a wireless receiver that connects to the user's iPod._ - **prototype** /ˈprəʊtətaɪp/ (noun, C1): the first version of a machine, built for testing. _Though it did not run well, the Doble brothers went on to build a second and third prototype in the following years._ - **virtual** /ˈvɜːtʃuəl/ (adjective, B2): created by computers to look and feel real. _Mobility will change in such potentially significant ways and in association with so many other technological developments, such as telepresence and virtual reality, that it is hard to make concrete predictions about the future._ - **cutting-edge** /ˌkʌtɪŋ ˈedʒ/ (adjective, C1): the newest and most advanced. _Many believe an entirely new approach to indoor farming is required, employing cutting-edge technologies._ - **sophisticated** /səˈfɪstɪkeɪtɪd/ (adjective, B2): advanced and complicated in design. _Shipbuilding today is based on science and ships are built using computers and sophisticated tools._ - **satellite** /ˈsætəlaɪt/ (noun, B2): a machine sent into space to travel around the earth. _Satellites, rocket shards and collision debris are creating major traffic risks in orbit around the planet._ - **infrastructure** /ˈɪnfrəstrʌktʃə/ (noun, C1): the basic systems and services something needs to work. _AI systems need a lot of data to function, but the public sector typically does not have the appropriate data infrastructure to support advanced machine learning._ - **infection** /ɪnˈfekʃn/ (noun, B2): an illness caused by bacteria or a virus. _In the future, our ability to manipulate microbes means we could construct buildings with useful microbes built into their walls to fight off infections._ - **chronic** /ˈkrɒnɪk/ (adjective, C1): (of illness) lasting a long time or keeps returning. _Further, it has recently been shown that rhesus monkeys kept on caloric-restricted diets for an extended time (nearly 15 years) have less chronic disease._ - **obesity** /əʊˈbiːsəti/ (noun, B2): being so overweight that it harms your health. _And research has found that access to even the most basic green spaces can provide a better quality of life for dementia sufferers and help people avoid obesity._ - **symptom** /ˈsɪmptəm/ (noun, B2): a sign that someone has an illness. _In a study of over 200 patients with Alzheimer's disease, a degenerative brain disease, bilingual patients reported showing initial symptoms of the disease an average of five years later than monolingual patients._ - **immune** /ɪˈmjuːn/ (adjective, C1): not affected by a disease, poison or chemical. _Not to be left behind are the disease-spreading pests, about 100 species of which have become immune to a variety of insecticides now in use._ - **nutrition** /njuˈtrɪʃn/ (noun, B2): the food you eat and how it affects your health. _Improvements in childhood nutrition in the first quarter of the twentieth century, for example, gave today's elderly people a better start in life than their predecessors._ - **mortality** /mɔːˈtæləti/ (noun, C1): the number of deaths in a group or period. _Macfarlane says: "The infant mortality rate halved in the space of 20 years, and this happened in both rural areas and cities, and across all classes._ - **epidemic** /ˌepɪˈdemɪk/ (noun, C1): a disease that spreads quickly to many people, animals or plants. _A first epidemic, which occurred in the 1920s, gradually died down, but in the '70s a second epidemic was triggered by shipments of elm from Canada._ - **outbreak** /ˈaʊtbreɪk/ (noun, B2): the sudden start of a disease or something unpleasant. _In 2015, an outbreak of haemorrhagic septicaemia, caused by the normally harmless bacterium Pasteurella multocida, killed over 75% of the global adult saiga population in just three weeks._ - **antibiotic** /ˌæntibaɪˈɒtɪk/ (noun, B2): a medicine that kills bacteria. _Our obsession with hygiene, our overuse of antibiotics and our unhealthy, low-fibre diets are disrupting the bacterial balance and may be responsible for soaring rates of allergies and immune problems, such as inflammatory bowel disease (IBD)._ - **pharmaceutical** /ˌfɑːməˈsuːtɪkl/ (noun, C1): medicines, or the businesses that make them. _Pharmaceuticals is one of the most profitable industries in North America._ - **cardiovascular** /ˌkɑːdiəʊˈvæskjələ/ (adjective, C1): relating to the heart and blood vessels. _When we are exposed to too much noise over the long term, however, those responses can lead to a multitude of health issues, from sleep disturbance to even cardiovascular disease._ - **respiratory** /rəˈspɪrətri/ (adjective, C1): relating to breathing and the lungs. _She says families who switch to the smokeless cooking method could expect fewer respiratory diseases._ - **ailment** /ˈeɪlmənt/ (noun, C1): a minor illness. _Cinnamon was also reported to have health benefits, and was thought to cure various ailments, such as indigestion._ - **prescribe** /prɪˈskraɪb/ (verb, C1): (of a doctor) to say what medicine someone should take. _In Europe, only orthodox doctors can prescribe herbal medicine._ - **well-being** /ˌwel ˈbiːɪŋ/ (noun, B2): a state of good health and happiness. _"Wetlands directly support the livelihoods and well-being of millions of people," says Dr Matthew McCartney, principal researcher and hydrologist at the International Water Management Institute (IWMI)._ - **anxiety** /æŋˈzaɪəti/ (noun, B2): a feeling of worry and nervousness. _A tendency to procrastinate is linked to poor mental health, including higher levels of depression and anxiety._ - **fatigue** /fəˈtiːɡ/ (noun, C1): great tiredness of body or mind. _Apparently, unpredictable noise produces more fatigue than predictable noise, but it takes a while for this fatigue to take its toll on performance._ - **expectancy** /ɪkˈspektənsi/ (noun, C1): (with "life") the number of years someone will probably live. _The average captive animal will have a greater life expectancy compared with its wild counterpart, and will not die of drought, of starvation or in the jaws of a predator._ - **disorder** /dɪsˈɔːdə/ (noun, C1): an illness or condition that affects the mind or body. _In my previous research, I investigated how observing children at play can give us important clues about their well-being and can even be useful in the diagnosis of neurodevelopmental disorders like autism."_ - **psychological** /ˌsaɪkəˈlɒdʒɪkl/ (adjective, B2): relating to the mind and feelings. _Not only are the physical demands greater than most people could handle, athletes also face intense psychological pressure during competition._ - **hormone** /ˈhɔːməʊn/ (noun, B2): a chemical made in the body that controls its functions. _Our blood pressure goes up, muscles tense and glands release hormones that prepare us for fight or flight._ - **dementia** /dɪˈmenʃə/ (noun, C1): a brain illness that causes memory loss, often in old age. _Other diseases of old age - dementia, stroke, arteriosclerosis and emphysema - are also troubling fewer and fewer people._ - **aptitude** /ˈæptɪtjuːd/ (noun, C1): a natural ability to do something well. _Each division was organised in exactly the same way, used the same technology, did exactly the same kind of work, and had employees of comparable aptitudes._ - **manufacture** /ˌmænjuˈfæktʃə/ (noun, B2): the making of goods in large amounts. _Corkboard and cork tiles are ideal for thermal and acoustic insulation, while granules of cork are used in the manufacture of concrete._ - **productivity** /ˌprɒdʌkˈtɪvəti/ (noun, B2): how much work is done for the time or effort used. _When most people think of the costs of procrastination, they think of the toll on productivity._ - **commodity** /kəˈmɒdəti/ (noun, C1): a product or raw material that is bought and sold. _The world's wetlands are, unfortunately, rich sources for in-demand commodities, such as palm oil and pulpwood._ - **wage** /weɪdʒ/ (noun, B2): money paid for work, usually each week. _Factory workers had to work long hours in dangerous conditions for extremely low wages._ - **incentive** /ɪnˈsentɪv/ (noun, B2): something that encourages a person to do something. _It may sound strange but such payments need to be higher than the existing incentives for farmers to grow food crops._ - **entrepreneur** /ˌɒntrəprəˈnɜː/ (noun, B2): a person who starts and runs their own business. _A Chinese entrepreneur has figured out a way to manufacture 30-story, earthquake-proof skyscrapers that snap together in just 15 days._ - **workforce** /ˈwɜːkfɔːs/ (noun, B2): all the people employed in a company, industry or country. _In business as a whole, there are a number of factors encouraging the prospect of greater equality in the workforce._ - **recruitment** /rɪˈkruːtmənt/ (noun, C1): finding and employing new staff. _Problems of recruitment, remuneration and independence could also arise and this structure would not be appropriate for all companies._ - **consumer** /kənˈsjuːmə/ (noun, B2): a person who buys goods or services. _He also introduced the use of cellophane, the first transparent material for food packaging, which allowed consumers to see the quality of the product._ - **consumption** /kənˈsʌmpʃn/ (noun, B2): the eating, drinking or using of something. _Two thousand years ago, the inhabitants of South America's Andean mountains had a unique means of conserving potatoes for later consumption._ - **subsidy** /ˈsʌbsədi/ (noun, C1): money a government pays to help an industry or business. _In many places - not just the British Caribbean but Cuba and the Philippines too - a powerful sugar bourgeoisie played a major role in politics and their interests were consequently protected by trade barriers and subsidies._ - **recession** /rɪˈseʃn/ (noun, B2): a period when the economy shrinks and trade is poor. _In contrast to the many companies that responded to the recession by cutting prices, Coach saw the new consumer mindset as an opportunity for innovation and renewal._ - **lucrative** /ˈluːkrətɪv/ (adjective, C1): producing a lot of money. _By 1658, they had permanently expelled the Portuguese from the island, thereby gaining control of the lucrative cinnamon trade._ - **monopoly** /məˈnɒpəli/ (noun, C1): complete control of the trade in a product or service. _The Dutch now had a monopoly over the nutmeg trade which would last for another century._ - **competitive** /kəmˈpetətɪv/ (adjective, B2): relating to competing with rivals; better than rivals. _As a result, players and their teams are becoming increasingly creative with the modifications to their rackets as they look to maximise their competitive advantage._ - **executive** /ɪɡˈzekjətɪv/ (noun, B2): a senior manager in a company. _The company itself is based at Imperial College London, although Janssen, its chief executive, still lives in the UAE._ - **stakeholder** /ˈsteɪkhəʊldə/ (noun, C1): a person or group with an interest in a project or business. _Others, like Marcel Vernooij and Marcel Beukeboom, suggested that in order to "apply what we already know", all stakeholders, including business, government, scientists and civil society, must work together, starting at the beginning of the value chain._ - **turnover** /ˈtɜːnəʊvə/ (noun, C1): the rate at which staff leave and are replaced. _In addition, or maybe as a result, high employee turnover has been a recurring problem throughout the hospitality industry._ - **occupation** /ˌɒkjuˈpeɪʃn/ (noun, B2): a job or type of work. _According to a leading business consultancy, 3-14% of the global workforce will need to switch to a different occupation within the next 10-15 years, and all workers will need to adapt as their occupations evolve alongside increasingly capable machines._ - **affordable** /əˈfɔːdəbl/ (adjective, B2): cheap enough for most people to buy. _Finally, by the 1950s, refrigerator technology had developed far enough to make these appliances affordable for the average family._ - **expense** /ɪkˈspens/ (noun, B2): the money spent on something. _The chosen route ran beneath existing main roads to minimise the expense of demolishing buildings._ - **heritage** /ˈherɪtɪdʒ/ (noun, B2): history, buildings and traditions passed down from the past. _And it is the conservation of the world's cultural heritage against looting and careless harm._ - **indigenous** /ɪnˈdɪdʒənəs/ (adjective, C1): living in a place from the earliest times. _The first stage was achieved by Neolithic agrarians who were likely to have been indigenous to the British Isles._ - **ritual** /ˈrɪtʃuəl/ (noun, B2): a ceremony with actions always done the same way. _Alternatively, the carving may have been carried out during a Bronze or Iron Age ritual._ - **custom** /ˈkʌstəm/ (noun, B2): a traditional way of behaving in a society. _At the same time, they might help to preserve local customs, slowing the spread of habits associated with international English, such as its readiness to get on first-name terms._ - **civilisation** /ˌsɪvəlaɪˈzeɪʃn/ (noun, B2): a society with its own culture and way of life. _Although piracy in the Mediterranean is first recorded in ancient Egypt during the reign of Pharaoh Amenhotep III (c 1390-1353 BCE), it is reasonable to assume it predated this powerful civilisation._ - **inhabitant** /ɪnˈhæbɪtənt/ (noun, B2): a person or animal that lives in a place. _In the ancient times, the inhabitants of these areas relied heavily on marine resources, including fish and salt._ - **demographic** /ˌdeməˈɡræfɪk/ (adjective, C1): relating to a population's size, age and other features. _About three out of four families in Kenya depend on wood or charcoal to cook their daily meals, and the rate is even higher in rural areas, Kenya's latest demographic and health survey shows._ - **elderly** /ˈeldəli/ (adjective, B1): old (a polite word). _Elderly people are growing healthier, happier and more independent, say American scientists._ - **ethical** /ˈeθɪkl/ (adjective, B2): relating to what is morally right or wrong. _Knauft has observed that individuals in such groups don't accumulate property or possessions and have an ethical obligation to share everything._ - **prejudice** /ˈpredʒudɪs/ (noun, C1): an unfair opinion formed without good reason or knowledge. _In order to succeed, Whaley needs to get the local people on board, and that has meant overcoming local prejudices._ - **identity** /aɪˈdentəti/ (noun, B2): who a person is; a sense of belonging to a group. _Neuroscience has revealed which brain circuits are responsible for functions like understanding what other people think, empathy, fairness, and social identity._ - **minority** /maɪˈnɒrəti/ (noun, B2): a smaller group that is different from the rest. _Quite often, governments try to kill off a minority language by banning its use in public or discouraging its use in schools, all to promote national unity._ - **migration** /maɪˈɡreɪʃn/ (noun, B2): moving from one place to live in another. _They are so poor they have to live in slums and, as a result of migration, they may speak languages that are different from the regional language._ - **immigrant** /ˈɪmɪɡrənt/ (noun, B2): a person who comes to live permanently in a new country. _On a societal level, one could even imagine that a lack of conversational flow may hamper the integration of immigrants who have not completely mastered the language of their new country yet._ - **status** /ˈsteɪtəs/ (noun, B2): social or professional position compared with others. _Some cultural traditions demand solemn respect for academic status, for example, and it is only polite to respect this._ - **poverty** /ˈpɒvəti/ (noun, B2): the state of being very poor. _One response to the boycott movement has been the argument for the vital role palm oil plays in lifting many millions of people in the developing world out of poverty._ - **welfare** /ˈwelfeə/ (noun, C1): the health, safety and happiness of people. _When I ask fire science students to articulate the end, or purpose, of their field, they eventually generalize to something like, "The safety and welfare of society," which seems right._ - **norm** /nɔːm/ (noun, C1): an accepted standard way of behaving. _Etiquette-sensitive artificial translators could relieve people of the need to know these differing cultural norms._ - **hierarchy** /ˈhaɪərɑːki/ (noun, C1): a system that ranks people by importance or power. _In fact, research shows that, when innovating, the best approach is to create an environment devoid of structure and hierarchy and enable everyone involved to engage as one organic group._ - **ancestor** /ˈænsestə/ (noun, B2): a family member who lived a long time ago. _When our ancestors found themselves surrounded by hungry animals, they would have benefited from an increased ability to learn about hazards._ - **folklore** /ˈfəʊklɔː/ (noun, C1): the traditional stories and beliefs of a community. _Local folklore maintains that the statues walked, while researchers have tended to assume the ancestors dragged the statues somehow, using ropes and logs._ - **legacy** /ˈleɡəsi/ (noun, C1): something left by a person or period for later generations. _In collecting paintings that they loved, the sisters created a lasting and meaningful cultural legacy for the people of Wales and beyond._ - **artefact** /ˈɑːtɪfækt/ (noun, C1): an object made by people, especially long ago. _There they found numerous artefacts, including fragments of axes, some dating to about 14,000 years ago._ - **discipline** /ˈdɪsəplɪn/ (noun, C1): a subject or area of study. _An emerging discipline called neuroaesthetics is seeking to bring scientific objectivity to the study of art, and has already given us a better understanding of many masterpieces._ - **breakthrough** /ˈbreɪkθruː/ (noun, B2): an important new discovery or development. _Not long after that, Perkin made the scientific breakthrough that would bring him both fame and fortune._ - **hypothesis** /haɪˈpɒθəsɪs/ (noun, C1): an idea suggested to explain something, not yet proved. _Bones, tools and other artefacts found on the site seem to support this hypothesis._ - **empirical** /ɪmˈpɪrɪkl/ (adjective, C1): based on observation or experiment, not theory. _Despite all this, there is limited empirical evidence to suggest that streaming results in better outcomes for students._ - **specimen** /ˈspesɪmən/ (noun, C1): a single example of an animal or plant, used for study. _Sadly, the passenger pigeon's existence came to an end on 1 September 1914, when the last living specimen died at Cincinnati Zoo._ - **analysis** /əˈnæləsɪs/ (noun, B2): a detailed examination to understand something. _DNA analysis showed that all six species of bat had fed on economically important insect pests._ - **methodology** /ˌmeθəˈdɒlədʒi/ (noun, C1): the system of approaches and techniques used in a study. _It is in the light of an expectation that some observations are held to be relevant and some irrelevant, that one methodology is chosen and others discarded, that some experiments are conducted and others are not._ - **phenomenon** /fəˈnɒmɪnən/ (noun, B2): something that happens or exists, often unusual or interesting. _Urban farming is not, of course, a new phenomenon._ - **variable** /ˈveəriəbl/ (noun, C1): a factor that can change and affect results. _Analysing the trends in each variable, the researchers discovered that species with more flexible lifecycles were more likely to be able to benefit from an earlier emergence driven by climate change._ - **correlation** /ˌkɒrəˈleɪʃn/ (noun, C1): a link between two things that change together. _One interesting correlation Manton uncovered is that better-educated people are likely to live longer._ - **finding** /ˈfaɪndɪŋ/ (noun, B2): information discovered as a result of research. _According to the researchers, this unexpected finding may be down to the life experiences of children growing up in slums._ - **observation** /ˌɒbzəˈveɪʃn/ (noun, B2): watching something carefully to learn about it. _With exceptionally keen powers of observation and great finesse with a paintbrush, she recorded subtle nuances of colour, shape, and light that enlivened her paintings and attracted a wide audience._ - **investigate** /ɪnˈvestɪɡeɪt/ (verb, B2): to study something carefully to discover the truth. _My colleague and I, both neuroscientists, wanted to investigate how the mind operates under stress, so we visited some local fire stations._ - **quantify** /ˈkwɒntɪfaɪ/ (verb, C1): to measure something or express it as a number. _Alternatively, by comparing the experiences of identical twins with those of fraternal twins, who come from separate eggs and share on average half their DNA, researchers can quantify the extent to which our genes affect our lives._ - **replicate** /ˈreplɪkeɪt/ (verb, C1): to repeat a study to check that results are the same. _Professor of Psychology Timothy Bates, who has been trying to replicate Dweck's work, is finding that the results are repeatedly null._ - **genetic** /dʒəˈnetɪk/ (adjective, B2): relating to the cell units that parents pass to their children. _They compared the genetic structure of polar bears with that of their closest relatives from a warmer climate, the brown bears._ - **organism** /ˈɔːɡənɪzəm/ (noun, C1): a single living thing, such as a plant or animal. _In biological systems, organisms may display new characteristics that result from random genetic mutations._ - **evolution** /ˌiːvəˈluːʃn/ (noun, B2): gradual change in living things over many generations. _It is by now a truism that the story of human evolution is being rethought._ - **evolutionary** /ˌiːvəˈluːʃənri/ (adjective, C1): relating to how living things develop over time. _Like many others, Dawkins justifies his views with reference to the field of evolutionary psychology._ - **mutation** /mjuːˈteɪʃn/ (noun, C1): a change in a gene that can be passed on. _In humans, mutations of this gene are associated with increased risk of heart disease._ - **bacteria** /bækˈtɪəriə/ (noun, B2): tiny living things, some of which cause disease. _Once the water has drained away, bacteria and fungi then break down the carbon in the peat and turn it into CO₂ and methane._ - **rigorous** /ˈrɪɡərəs/ (adjective, C1): very careful, thorough and exact. _Once you have arrived at your hypothesis, which is a product of your imagination, you then proceed to a strictly logical and rigorous process, based upon deductive argument - hence the term 'hypothetico-deductive'._ - **excavation** /ˌekskəˈveɪʃn/ (noun, C1): digging in the ground to find ancient objects. _Archaeological excavations indicate that the Rapanui went to heroic efforts to protect the resources of their wind-lashed, infertile fields._ - **archaeological** /ˌɑːkiəˈlɒdʒɪkl/ (adjective, B2): relating to the study of ancient remains. _But to support this idea, they needed archaeological evidence for humans living in this remote area in the ancient past._ - **anecdotal** /ˌænɪkˈdəʊtl/ (adjective, C1): based on personal stories, not careful research. _Although quantitative evidence of AHI's initiatives at SAH are limited at present, anecdotal evidence clearly suggests that these practices are working._ - **criminal** /ˈkrɪmɪnl/ (adjective, B2): against the law; relating to illegal acts. _That course is presumably all about "means": how to detect and prosecute criminal activity._ - **sentence** /ˈsentəns/ (verb, C1): (of a judge) to give an official punishment. _Similar difficulties arose in the legal domain when algorithms were used in courts in the US to sentence criminals._ - **police** /pəˈliːs/ (verb, C1): to control something and make sure rules are obeyed. _Powerful artificial intelligence (AI) needs to be reliably aligned with human values, but does this mean AI will eventually have to police those values?_ - **punishment** /ˈpʌnɪʃmənt/ (noun, B2): a penalty for doing something wrong. _Pirate attacks on grain ships, which were essential to Roman citizens, led to angry voices in the Senate, demanding punishment of the culprits._ - **fraud** /frɔːd/ (noun, C1): deceiving people, often to get money. _These ranged from 'sensory leakage' - where clues about the pictures accidentally reach the receiver - to outright fraud._ - **legislation** /ˌledʒɪsˈleɪʃn/ (noun, C1): laws made by a government or parliament. _While policy makers struggle to define and implement appropriate legislation, development of the most destructive kind has continued apace over vast areas._ - **regulation** /ˌreɡjuˈleɪʃn/ (noun, B2): an official rule that controls an activity. _Along with biblical texts, the scrolls include documents about sectarian regulations and religious writings that do not appear in the Old Testament._ - **illegal** /ɪˈliːɡl/ (adjective, B1): not allowed by law. _Manatee hunting is now illegal in every country the African species is found in._ - **enforce** /ɪnˈfɔːs/ (verb, C1): to make sure people obey a law or rule. _Local authorities in London are campaigning to be allowed to enforce anti-pollution laws themselves; at present only the police have the power to do so, but they tend to be busy elsewhere._ - **justice** /ˈdʒʌstɪs/ (noun, B2): fair treatment of people. _In the past, the case for public transport has been made on the basis of environmental and social justice considerations rather than economics._ - **victim** /ˈvɪktɪm/ (noun, B2): a person harmed by a crime, accident or illness. _He believes the perennial theme of women as victims in stories like "Little Red Riding Hood" explains why they continue to feel relevant._ - **security** /sɪˈkjʊərəti/ (noun, B2): protection against attack, crime or danger. _Many researchers have warned against the rolling out of AI without appropriate security standards and defence mechanisms._ - **permit** /ˈpɜːmɪt/ (noun, B2): an official document that allows you to do something. _"If ranchers don't have a dead cow, they will not make a call to apply for a permit to kill a wolf."_ - **dispute** /dɪˈspjuːt/ (noun, C1): a serious disagreement between people or groups. _And disputes over shared water resources have led to violence and continue to raise local, national and even international tensions._ - **abuse** /əˈbjuːs/ (noun, B2): wrong or harmful use of something, such as power. _Not surprisingly, biometrics raise thorny questions about privacy and the potential for abuse._ - **regulatory** /ˈreɡjələtəri/ (adjective, C1): having the job of controlling an activity through rules. _But she adds that taking the work further would be expensive because of the need to pay for a licence for the CRISPR technology and get regulatory approval._ - **transmit** /trænzˈmɪt/ (verb, C1): to send or pass on a signal or message. _And in a twelve-year programme of work, Ryabko and Reznikova have found evidence that ants can transmit very complex messages._ - **publication** /ˌpʌblɪˈkeɪʃn/ (noun, B2): the act of printing and releasing a book or text. _After its publication, his Dictionary was not seriously rivalled for over a century._ - **advertising** /ˈædvətaɪzɪŋ/ (noun, B1): telling people about products to make them buy them. _In 1954, the company adapted some of Birdseye's freezing techniques, and with the help of a clever name and a huge advertising budget, it launched the first 'TV Dinner'._ - **audience** /ˈɔːdiəns/ (noun, B1): the people who watch, listen to or read something. _While less technical than the research paper on which the chapter is based, it is probably more technical than would be preferred by a general audience._ - **narrative** /ˈnærətɪv/ (noun, C1): a story or account of events. _"Studies on hunter-gatherer folk tales suggest that these narratives include really important information about the environment and the possible dangers that may be faced there - stuff that's relevant to survival," he says._ - **documentary** /ˌdɒkjuˈmentri/ (noun, B1): a film or programme that gives facts about a real subject. _In 2019, while making a documentary, David Scheel of Alaska Pacific University in the USA housed an octopus named Heidi in a tank in his living room._ - **verbal** /ˈvɜːbl/ (adjective, B2): spoken; using words rather than actions. _People likely have lied to one another for roughly as long as verbal communication has existed._ - **gesture** /ˈdʒestʃə/ (noun, B2): a movement of the hand or head that shows meaning. _Similarly, in the Museum of Natural History in Washington, Neanderthal man is shown making a dominant gesture to his wife._ - **linguistic** /lɪŋˈɡwɪstɪk/ (adjective, C1): relating to language. _Modern science - linguistic, archaeological and genetic evidence - has definitively proved the moai builders were Polynesians, but not how they moved their creations._ - **convey** /kənˈveɪ/ (verb, C1): to make ideas, feelings or information known. _This sleek design allows single sounds to convey useful information, and in fact even the absence of a sound has been enlisted to express something specific._ - **interpretation** /ɪnˌtɜːprəˈteɪʃn/ (noun, C1): an explanation of what something means. _Everything the brain sees, hears, or touches has multiple interpretations._ - **coverage** /ˈkʌvərɪdʒ/ (noun, C1): the reporting of news by TV, radio and newspapers. _This is surprising considering the high level of media coverage on this issue._ - **press** /pres/ (noun, B2): newspapers and magazines and the journalists who write them. _His work was enthusiastically welcomed by fellow sculptors, but the reviews in the press were extremely negative and turned Moore into a notorious figure._ - **campaign** /kæmˈpeɪn/ (noun, B2): a planned set of actions to achieve a goal. _This leads us to our third observation: a campaign to correct misinformation, even if rhetorically compelling, requires resources and planning to accomplish necessary reach and frequency._ - **persuade** /pəˈsweɪd/ (verb, B1): to make someone agree or act by giving reasons. _Leading us gently by the hand, he takes us into the world of microbes - a bizarre, alien planet - in a bid to persuade us to love them as much as he does._ - **distort** /dɪˈstɔːt/ (verb, C1): to change facts or images so they are no longer true. _One of London Zoo's recent advertisements caused me some irritation, so patently did it distort reality._ - **medium** /ˈmiːdiəm/ (noun, C1): a way of communicating or expressing something. _Further, it will adapt to that environment's requirements - from different writing systems to the characteristics of whatever medium is used._ - **settlement** /ˈsetlmənt/ (noun, B2): a place where people have come to live. _Today, four out of five of its people live in single-storey informal settlements on the spreading edges of the city, where the journey to and from the centre regularly takes over two hours._ - **urban** /ˈɜːbən/ (adjective, B2): relating to towns and cities. _In Paris, urban farmers are trying a soil-free approach to agriculture that uses less space and fewer resources._ - **congestion** /kənˈdʒestʃən/ (noun, C1): too much traffic, so that movement is slow. _Despite the extension of the underground railway, by the 1880s, congestion on London's streets had become worse._ - **suburb** /ˈsʌbɜːb/ (noun, B2): an area where people live on the edge of a city. _Melbourne's large tram network has made car use in the inner city much lower, but the outer suburbs have the same car-based structure as most other Australian cities._ - **sprawl** /sprɔːl/ (noun, C1): the spread of a city into the land around it. _Urban sprawl means that life without a car is next to impossible._ - **residential** /ˌrezɪˈdenʃl/ (adjective, B2): (of an area or building) where people live, not work. _In California, where population growth has averaged more than 600,000 a year for at least a decade, more residential housing is being built._ - **high-rise** /ˈhaɪ raɪz/ (noun, B2): a very tall building with many floors. _Mass-produced, low-cost high-rises seemed to offer a solution to the problem of housing a growing inner-city population._ - **inner-city** /ˌɪnə ˈsɪti/ (adjective, C1): in the old central area of a large town, often poor. _His idea was to relocate the poor workers who lived in the inner-city slums to newly constructed suburbs, and to provide cheap rail travel for them to get to work._ - **tourism** /ˈtʊərɪzəm/ (noun, B1): the business of providing services for people on holiday. _Tourism currently makes up 9% of the country's gross domestic product, and is the country's largest export sector._ - **destination** /ˌdestɪˈneɪʃn/ (noun, B1): the place someone or something is going to. _Large merchant ships would approach the destination port and, just like today, be intercepted by a number of towboats that would drag them to the quay._ - **accommodation** /əˌkɒməˈdeɪʃn/ (noun, B1): a place to live or stay. _The explosion in demand for accommodation in the inner suburbs of Melbourne suggests a recent change in many people's preferences as to where they live._ - **overcrowded** /ˌəʊvəˈkraʊdɪd/ (adjective, B2): with too many people in one place. _The area within consisted of poorly built, overcrowded slums and the streets were full of horse-drawn traffic._ - **municipal** /mjuːˈnɪsɪpl/ (adjective, C1): belonging to or run by a town or city. _These correspond roughly to small municipal, medium-sized metropolitan and major metropolitan airports respectively, and encompass an increasingly rigorous set of regulations._ - **density** /ˈdensəti/ (noun, C1): how many people or things are in an area. _With such small population densities, it seems unlikely that prehistoric hunter-gatherer groups had to compete against each other for resources or had any need to develop ruthlessness and competitiveness, or to go to war._ - **voyage** /ˈvɔɪɪdʒ/ (noun, B2): a long journey, especially by sea. _It also seemed likely that these islands were crucial "stepping stones" on humans' island-hopping voyages through this region millennia ago._ - **landmark** /ˈlændmɑːk/ (noun, B2): a building or feature that is easy to recognise. _They sailed by noting their position relative to a succession of recognisable landmarks._ - **architecture** /ˈɑːkɪtektʃə/ (noun, B1): the design and style of buildings. _Although the Renaissance is renowned as an era of incredible progress in art and architecture, it is rarely noted that the 15th century also marked the birth of urbanism as a true academic discipline._ - **sanitation** /ˌsænɪˈteɪʃn/ (noun, C1): systems for clean water and removing human waste. _This rapid urbanisation brought significant challenges, as overcrowded cities suffered from pollution and inadequate sanitation._ - **mobility** /məʊˈbɪləti/ (noun, C1): the ability to move or travel easily. _During Phase II, from January to February 1991, a number of approaches were implemented in an effort to improve mobility and access to transport._ - **housing** /ˈhaʊzɪŋ/ (noun, B2): houses and flats, especially for many people. _During this period, there was an emphasis on providing clean water, improved sanitation and housing._ - **expedition** /ˌekspəˈdɪʃn/ (noun, B2): an organised journey to explore a place. _Between 1906 and 1908 he had taken part in a highly publicized and extremely dangerous expedition to the coast of northeast Greenland._ - **navigate** /ˈnævɪɡeɪt/ (verb, C1): to find your way through or around a place. _Outside the centre many rely on boda boda (motorbike taxis) to navigate the narrow side streets and potholed mud roads that make up much of the metropolis._ - **comprehend** /ˌkɒmprɪˈhend/ (verb, C1): to understand something fully. _Even if it can be technically explained (and that's not always the case), AI's decision-making process is usually too difficult for most people to comprehend._ - **abundant** /əˈbʌndənt/ (adjective, C1): existing in large amounts; more than enough. _Canned foods were rationed to save tin for the war effort, while frozen foods were abundant and cheap._ - **scarce** /skeəs/ (adjective, B2): not available in large enough amounts. _When food is scarce, bats become a crucial source of protein for local people._ - **autonomous** /ɔːˈtɒnəməs/ (adjective, C1): able to act and decide independently. _The purpose of teaching is to provide and then gradually remove this 'scaffolding' until they are autonomous._ - **reputation** /ˌrepjuˈteɪʃn/ (noun, B2): the opinion that people generally have of someone. _Such daring compositions helped establish O'Keeffe's reputation as an innovative modernist._ - **significant** /sɪɡˈnɪfɪkənt/ (adjective, B2): large or important enough to have a noticeable effect. _This rapid urbanisation brought significant challenges, as overcrowded cities suffered from pollution and inadequate sanitation._ - **considerable** /kənˈsɪdərəbl/ (adjective, B2): large in size, amount or degree. _There has been a considerable amount of research on high performance over the last century that suggests it goes way beyond tested intelligence._ - **substantial** /səbˈstænʃl/ (adjective, B2): large in amount or importance. _Despite the Egyptian fleet's best efforts, the pirates continued to cause substantial disruption to regional commerce._ - **crucial** /ˈkruːʃl/ (adjective, B2): extremely important, because other things depend on it. _There are some crucial lessons here for everyone aiming to boost investments in national AI programmes._ - **fundamental** /ˌfʌndəˈmentl/ (adjective, B2): basic and most important. _The environmental practices of big businesses are shaped by a fundamental fact that for many of us offends our sense of justice._ - **inevitable** /ɪnˈevɪtəbl/ (adjective, B2): certain to happen and impossible to avoid. _Such is our dependence on fossil fuels, and such is the volume of carbon dioxide already released into the atmosphere, that many experts agree that significant global warming is now inevitable._ - **approximately** /əˈprɒksɪmətli/ (adverb, B2): close to a number but not exactly. _It had rowers in the top, middle and lower levels, and approximately 50 rowers in each bank._ - **estimate** /ˈestɪmeɪt/ (verb, B2): to judge a number or amount roughly from the facts known. _The World Health Organization estimates that about 14,300 Kenyans die annually as a result of indoor air pollution - most of which is caused by cooking and heating sources._ - **indicate** /ˈɪndɪkeɪt/ (verb, B2): to show or suggest that something is true. _The evidence indicates that guard dogs are highly effective._ - **assumption** /əˈsʌmpʃn/ (noun, B2): something accepted as true without proof. _There has long been a general assumption that human beings are essentially selfish._ - **contribute** /kənˈtrɪbjuːt/ (verb, B2): to be one of the causes of something. _These factors mean that they may not be as accessible to the general public, require more energy to run and contribute to urban heat._ - **enhance** /ɪnˈhɑːns/ (verb, C1): to improve the quality, amount or value of something. _Indeed, Australian researchers are now using dogs to enhance biodiversity and create refuges for species threatened by predation._ - **facilitate** /fəˈsɪlɪteɪt/ (verb, C1): to make a process easier or more likely. _This 'mental break' might facilitate the replenishment of mental resources._ - **diminish** /dɪˈmɪnɪʃ/ (verb, C1): to become smaller, weaker or less important. _Though the practical need for a common language will diminish, the social value of sharing one will persist._ - **fluctuate** /ˈflʌktʃueɪt/ (verb, C1): to change often between higher and lower levels. _In the temperate zone in spring, temperatures fluctuate greatly from day to day, but day length increases steadily by a predictable amount._ - **comprise** /kəmˈpraɪz/ (verb, C1): to be made up of particular parts. _Peat comprises 90 per cent water, so this is one of the most alarming consequences of peatland clearances._ - **exceed** /ɪkˈsiːd/ (verb, C1): to be greater than a number or amount. _Janssen says that by 2030 half of the world's population will be living with water stress - where the demand exceeds the supply over a certain period of time._ - **implication** /ˌɪmplɪˈkeɪʃn/ (noun, C1): a likely effect or result of something. _In fact, some of the island's insectivorous bats are currently thriving and this has important implications for farmers and conservationists alike._ - **perception** /pəˈsepʃn/ (noun, C1): the way people see or understand something. _It is worth noting that contrary to popular perception, rowers were not slaves but mostly Roman citizens enrolled in the military._ - **predominantly** /prɪˈdɒmɪnəntli/ (adverb, C1): mostly; mainly. _While the Mediterranean region is predominantly fertile, some parts are rugged and hilly, even mountainous._ - **sufficient** /səˈfɪʃnt/ (adjective, B2): enough for a particular purpose. _If necessary, they will chase away predators, but often their mere presence is sufficient._ - **plausible** /ˈplɔːzəbl/ (adjective, C1): seeming reasonable and likely to be true. _Perhaps the most plausible suggestion as to why leaves would go to the trouble of making anthocyanins when they're busy packing up for the winter is the theory known as the 'light screen' hypothesis._ - **controversial** /ˌkɒntrəˈvɜːʃl/ (adjective, B2): causing a lot of public disagreement. _More controversial is the date of the enigmatic Long Man of Wilmington in Sussex._ - **ambiguous** /æmˈbɪɡjuəs/ (adjective, C1): having more than one possible meaning. _As with error correction, however, there's a limit beyond which messages become too ambiguous._ - **profound** /prəˈfaʊnd/ (adjective, C1): very great or deeply felt. _Thus, tourism has a profound impact both on the world economy and, because of the educative effect of travel and the effects on employment, on society itself._ - **unprecedented** /ʌnˈpresɪdentɪd/ (adjective, C1): never having happened or existed before. _Unprecedented construction of tens of thousands of monumental engineering projects designed to control floods, protect clean water supplies, and provide water for irrigation and hydropower brought great benefits to hundreds of millions of people._ - **widespread** /ˈwaɪdspred/ (adjective, B2): existing or happening in many places. _In recent years, however, as increased efforts have been made to protect wild animals, predators have become more widespread again._ - **prevalent** /ˈprevələnt/ (adjective, C1): common in a particular place or time. _These were the traits that were prevalent in human life for tens of thousands of years._ - **distinctive** /dɪˈstɪŋktɪv/ (adjective, C1): having a quality that makes it easy to recognise. _They are also looking at whether the types of pottery used, and other aspects of their material culture, were distinctive to specific regions or were more similar across larger areas._ - **equivalent** /ɪˈkwɪvələnt/ (noun, C1): something with the same value, use or purpose. _She was the only woman to win the Fields Medal - the mathematical equivalent of a Nobel prize._ - **notion** /ˈnəʊʃn/ (noun, C1): an idea or belief. _There is significant evidence to back this notion from contemporary hunter-gatherer groups, who live in the same way as prehistoric humans did._ - **framework** /ˈfreɪmwɜːk/ (noun, C1): a set of ideas used to understand or decide things. _Implicit theories provide a framework that is useful in defining the general scope of a phenomenon - especially a not-well-understood phenomenon._ - **criterion** /kraɪˈtɪəriən/ (noun, C1): a standard used to judge or decide something. _A majority of the contemporary definitions of play focus on several key criteria._ - **extent** /ɪkˈstent/ (noun, B2): how large, important or serious something is. _Not everyone will benefit from silence to the same extent, but Ben-Soussan says one characteristic is key: the person must need to want to engage in the experience._ - **consensus** /kənˈsensəs/ (noun, C1): general agreement among a group of people. _While there is consensus among the majority of modern scholars that Stonehenge once served the function of burial ground, they have yet to determine what other purposes it had._ - **dilemma** /dɪˈlemə/ (noun, C1): a difficult situation with no easy solution. _Whatever the cause, the dilemma is always the same: what happens if these new, external sources of income dry up?_ - **constraint** /kənˈstreɪnt/ (noun, C1): something that limits what you can do. _Machines will be free of many of the physical constraints on human intelligence._ - **obstacle** /ˈɒbstəkl/ (noun, B2): something that blocks your way or stops progress. _The Romans dug tunnels for their roads using the counter-excavation method, whenever they encountered obstacles such as hills or mountains that were too high for roads to pass over._ - **drawback** /ˈdrɔːbæk/ (noun, B2): a disadvantage or problem. _A major drawback of vertical farming, however, is that the plants would require artificial light._ - **adverse** /ˈædvɜːs/ (adjective, C1): harmful or unpleasant. _We asked the firefighters to estimate their likelihood of experiencing 40 different adverse events in their life, such as being involved in an accident or becoming a victim of card fraud._ - **beneficial** /ˌbenɪˈfɪʃl/ (adjective, B2): having a good or helpful effect. _Researchers are also seeking to understand what aspects of silent experiences are most beneficial to our health._ - **detrimental** /ˌdetrɪˈmentl/ (adjective, C1): causing harm or damage. _This assumption has also fostered the idea that disorder must be detrimental to organisational productivity._ - **susceptible** /səˈseptəbl/ (adjective, C1): easily affected or harmed by something. _Wood expands as it absorbs moisture from the air and is susceptible to pests, not to mention fire._ - **vulnerable** /ˈvʌlnərəbl/ (adjective, B2): easily hurt or harmed. _It's thought that they don't experience REM sleep because during REM sleep animals are more vulnerable to extremes of temperature._ - **viable** /ˈvaɪəbl/ (adjective, C1): able to work successfully. _The brothers made one final attempt to produce a viable steam automobile._ - **sustain** /səˈsteɪn/ (verb, C1): to provide what is needed to keep someone alive. _The Desolenator can produce 15 litres of drinking water per day, enough to sustain a family for cooking and drinking._ - **accumulate** /əˈkjuːmjəleɪt/ (verb, C1): to collect more and more of something over time. _We're apparently ruthless, with strong impulses to compete against each other for resources and to accumulate power and possessions._ - **compensate** /ˈkɒmpenseɪt/ (verb, C1): to balance a bad effect with something good. _The study suggests that people who smoke cigarettes are continually damaging their cardiovascular system, which adapts in order to compensate for the effects of smoking._ - **deteriorate** /dɪˈtɪəriəreɪt/ (verb, C1): to become worse. _But the vast majority of animals deteriorate with age just like people do._ - **inhibit** /ɪnˈhɪbɪt/ (verb, C1): to slow down or prevent a process. _Positive emotions facilitate the creative aspects of learning and negative emotions inhibit it._ - **tendency** /ˈtendənsi/ (noun, B2): a likelihood to behave or think in a particular way. _This suggests people use relevant evidence about AI in a biased manner to support their existing attitudes, a deep-rooted human tendency known as "confirmation bias"._ - **subtle** /ˈsʌtl/ (adjective, C1): small and not easy to notice. _Another change was so subtle as to pass more or less unnoticed._ - **comprehensive** /ˌkɒmprɪˈhensɪv/ (adjective, B2): including all or nearly all parts. _The impression is that the logical nature of the textbooks and their comprehensive coverage of different types of examples, combined with the relative homogeneity of the class, renders work sheets unnecessary._ - **intricate** /ˈɪntrɪkət/ (adjective, C1): having many small parts arranged in a complicated way. _Unfortunately, all of the precautions and intricate design of the underground network did not prevent ancient robbers from finding a way in._ - **conventional** /kənˈvenʃənl/ (adjective, B2): usual or traditional. _Using these insights, Coach launched the lower-priced Poppy handbags, which were in vibrant colors, and looked more youthful and playful than conventional Coach products._ - **abrupt** /əˈbrʌpt/ (adjective, C1): sudden and unexpected. _These abrupt changes will produce either positive or negative feelings._ - **merely** /ˈmɪəli/ (adverb, B2): only; nothing more than. _These notions merely label rather than explain the evolution of human innovations._ - **virtually** /ˈvɜːtʃuəli/ (adverb, B2): almost completely. _Because identical twins come from a single fertilized egg that splits into two, they share virtually the same genetic code._