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: Introns are regions that do not code for proteins.
[A]: introns DNA.


[Q]: Fact: Many corals secrete an exoskeleton that builds up to become a coral reef.
[A]: coral exoskeleton is made of carbonate.


[Q]: Fact: Light enters the eye through an opening called the pupil.
[A]:
eyes are used to see.