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.

Example Input: Fact: temperature changing can cause phase changes.
Example Output: : temperature heat.

Example Input: Fact: Adolescence is a time of significant mental, emotional, and social changes.
Example Output: Adolescence.

Example Input: Fact: stomata closing reduces water loss.
Example Output:
plants need water to live.