# PTE RW FIB #29: Evolutionary Biology and Animal...

Reading & Writing: Fill in the Blanks #29 - Level 3 - Feeds Reading

> Below is a text with blanks. Click on each blank, a list of choice will appear. Select the appropriate answer choice for each blank.

A creature may have fine physical defenses such as hard armor or sharp spines. It may have powerful chemical defenses such as an ____ smell or a foul taste but none of these defenses is much used in the ____ for survival unless the animal also has the right behavior to go with it. Evolution shapes a living creature's size and color, and it also ____ an animal's actions and behavioral patterns. The most ____ behaviors are instinctive or in-built. In other words, the creatures can perform the actions without having to learn what to do it by ____ and error.

## Answer

A creature may have fine physical defenses such as hard armor or sharp spines. It may have powerful chemical defenses such as an **appalling** smell or a foul taste but none of these defenses is much used in the **struggle** for survival unless the animal also has the right behavior to go with it. Evolution shapes a living creature's size and color, and it also **shapes** an animal's actions and behavioral patterns. The most **automatic** behaviors are instinctive or in-built. In other words, the creatures can perform the actions without having to learn what to do it by **trial** and error.

## Explanation

Blank 5 completes the fixed phrase "trial and error," meaning learning by trying things. "Attempt and error" is not used. In blank 1, a defensive smell must be unpleasant to work, and "foul taste" confirms this. So "appalling" fits, while "agreeable" and "enchanting" mean pleasant.

## Hints

- Look for words that contrast with positive traits to describe chemical defenses.
- Consider the phrase 'trial and error' as a common idiomatic expression.

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