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: If a rub two rocks together after awhile they will start to? Answer: Get smooth.
[EX A]: contact between rocks over long periods of time causes rocks to smooth

[EX Q]: Question: An example of combining two substances is? Answer: pouring queso into guacamole.
[EX A]: An example of combining two substances is pouring one substance into the other substance

[EX Q]: Question: If it starts raining acid rain you should? Answer: Move the car to the garage.
[EX A]:
acid rain has a negative impact on water quality