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.

Fact: Playing is just one of many ways that mammals and other animals learn how to behave.
animal kitten.

Fact: burning fossil fuels increases the carbon in the atmosphere.
carbon atmosphere.

Fact: All cnidarians are aquatic.

all aquatic water.