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 sandbar is formed by water moving sediment downstream.

A: sandbar habitat.
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Q: Fact: Evolution occurs in response to a change in the environment.

A: Evolution is Evolution is change in the heritable characteristics.
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Q: Fact: waxy leaves are used for storing water by some plants.

A:
plants storing water.
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