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: transpiration is when water vapor moves from plants into the atmosphere.
Example Output: atmosphere air.

Example Input: Fact: Dilation occurs when cell walls relax.
Example Output: Dilation occurs when cell walls relax.

Example Input: Fact: Vesicle transport requires energy, so it is also a form of active transport.
Example Output:
Vesicle transport.