Write a correct answer to the given question based on its associated fact. Make sure that your answer is contained in the associated fact. Don't be creative and introduce any new word that is not mentioned in the associated fact! Remember that the associated fact has been rearranged to form the question. So, the correct answer words must lie within the associated fact. The correct answer can be a word, phrase, or even a sentence.

[EX Q]: Fact: heat is detected by sensory nerve cells. 
Question: What is detected by sensory nerve cells?
[EX A]: heat.

[EX Q]: Fact: killing microorganism in food is important to food safety. 
Question: killing microorganisms in food is important to?
[EX A]: food safety.

[EX Q]: Fact: Playing is just one of many ways that mammals and other animals learn how to act. 
Question: What is one of the ways that mammals and other animals learn how to act?
[EX A]:
playing.