# Flawed Beauty: the problem with toughened glass: answers and explanations

Cambridge IELTS 5, Test 4, Reading Passage 2

Source: Passage, questions and answer key from Cambridge IELTS 5, Test 4, Reading Passage 2. © Cambridge University Press & Assessment. Used for educational practice. Explanations and evidence notes are written by Testmigo.

## Answer key

| Q | Answer | Proof |
| --- | --- | --- |
| 14 | G | But he insists that cases are few and far between. ... It's a very rare phenomenon |
| 15 | A | What you hear is only the tip of the iceberg ... No-one wants bad press. |
| 16 | H | the oldest pane of toughened glass known to have failed due to nickel sulphide inclusions |
| 17 | C | analysed every glass pane in the building. |
| 18 | F | it shatters into tiny cubes rather than large, razor-sharp shards. |
| 19 | I | shattered without warning and fell from its frame. ... The time that elapses before failure occurs is unpredictable. |
| 20 | C | and then cooling it rapidly with jets of cold air. |
| 21 | K | This causes the outer layer of the pane to contract and solidify before the interior. |
| 22 | E | although if the glass is heated - by sunlight, for example - the process is speeded up. ... a particularly hot day |
| 23 | L | But he insists that cases are few and far between. ... Others disagree. |
| 24 | TRUE | had almost certainly caused the failure. |
| 25 | NOT GIVEN | This glass has five times the strength of standard glass ... large panels can be bolted together to make transparent walls |
| 26 | FALSE | Data showing the scale of the nickel sulphide problem is almost impossible to find. |

## Why these answers are right

**14. G.** Brian Waldron admits the glass industry knows about the issue, but insists that cases are "few and far between" and calls it "a very rare phenomenon". That matches G, the claim that nickel sulphide failure is very unusual.

**15. A.** Trevor Ford says what people hear "is only the tip of the iceberg" and gives the reason: "No-one wants bad press." In other words, many failures are kept quiet, which matches A, that publicity about nickel sulphide failure has been suppressed.

**16. H.** Graham Dodd points out that the oldest pane known to have failed from nickel sulphide inclusions, in Pilkington's research building at Lathom, was 27 years old. The longest known delay before a pane broke is the most extreme case of delayed failure, so the answer is H.

The why and the trap for questions 17 onwards are free with an account on the [answers page](https://testmigo.com/ielts/reading/flawed-beauty-the-problem-with-toughened-glass/answers).

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