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.

Input: Consider Input: Fact: Sex hormones are chemical messengers that control sexual development and reproduction.

Output: chemical messengers carry signals.


Input: Consider Input: Fact: coal is used for generating heat by burning.

Output: burning coal pollution.


Input: Consider Input: Fact: the digestive system breaks food into nutrients for the body.


Output: breaking food down.