instruction:
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.
question:
Fact: nuclear reactions in stars causes stars to produce light.
answer:
light contains photons.


question:
Fact: a freezer is used for cooling things.
answer:
cooling food helps it last longer.


question:
Fact: Evolution is a change in the characteristics of living things over time.
answer:

Evolution.