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.

[EX Q]: Fact: Lions live in social groups called prides.
[EX A]: Lion.

[EX Q]: Fact: Arteries generally carry oxygen-rich blood.
[EX A]: Arteries generally carry oxygen-rich blood.

[EX Q]: Fact: dropping an object into water causes vibrations in the water.
[EX A]:
Vibration.