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: Vesicle transport requires energy, so it is also a form of active transport.
[A]: Vesicle transport.


[Q]: Fact: when a river floods , that river deposits soil in flood plains.
[A]: flood cause.


[Q]: Fact: natural magnetism is used for pointing north by a compass.
[A]:
a compass is used for.