In this task, you need to write a topic word from the given fact. The topic word must have at least one word overlap with the given fact. The topic word often involves adding a new word from a related concept. In your topic word, use at least one word from the given fact. Topic words with two or more words work best.

[Q]: Fact: a compass is used for determining direction.
[A]: compass direction.


[Q]: Fact: Food is easier to chew because it is moistened by saliva from the salivary glands.
[A]: bolus saliva.


[Q]: Fact: Evolution occurs in response to a change in the environment.
[A]:
Evolution is Evolution is change in the heritable characteristics.