In this task, you are given a question and a corresponding answer. Your task is to generate a fact statement that is useful in answering the given question.

[EX Q]: Question: I need electrical energy to? Answer: cook some bread.
[EX A]: a light bulb requires electrical energy to produce light

[EX Q]: Question: If I run my finger across a sheet of plain paper and a sheet of sand paper, which will have greater friction? Answer: the sand paper.
[EX A]: as the roughness of something increases , the friction of that something will increase when its surface moves against another surface

[EX Q]: Question: Which causes the electric fan to work? Answer: power outlets allow the blades to rotate.
[EX A]:
the vanes rotating in an electric fan causes air to move