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.

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

[Q]: Question: Illness has a negative impact on the health of what? Answer: llamas.
[A]: illness has a negative impact on an organism 's health

[Q]: Question: What does pencil lead contain? Answer: stable carbon.
[A]:
pencil lead contains mineral graphite