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.

[Q]: Fact: Birds have a large brain relative to the size of their body.
[A]: bird brain body.


[Q]: Fact: a thermometer is used to measure temperature.
[A]: Temperature derermine weather.


[Q]: Fact: Collar cells have tiny hairs that trap the particles.
[A]:
Collar cells tiny hairs.