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: who would see better through an underground tunnel? Answer: a man with a candle and match.
[EX A]: a candle is a source of light when it is burned

[EX Q]: Question: It's most likely to rain when the color of the sky looks? Answer: dark and Silvery.
[EX A]: grey clouds appear before precipitation

[EX Q]: Question: A chemical reaction may occur when _____ is added to an object.? Answer: warmth.
[EX A]:
adding heat to an object sometimes causes chemical reactions