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.

[EX Q]: Fact: if fossils of a water animal or plant are found in a place then that place used to be covered by water in the past.
[EX A]: fish water animal.

[EX Q]: Fact: Heterotrophs get food by eating other living things.
[EX A]: Heterotrophs.

[EX Q]: Fact: gills are used for breathing water by aquatic animals.
[EX A]:
aquatic animals gills.