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: The mounds at the beach are made of? Answer: silica.
[EX A]: sand dunes are made of sand

[EX Q]: Question: A fan pushes air with? Answer: rotating flat surface.
[EX A]: the vanes rotating in an electric fan causes air to move

[EX Q]: Question: What phenomenon is best described as evaporation? Answer: steam coming from hot cocoa.
[EX A]:
evaporation causes amount of water to decrease