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: many chemical messengers that control body functions are proteins. 
Question: What are many chemical messengers that control body functions?
[EX A]: proteins.

[EX Q]: Fact: Burning fuel in furnaces can kill. 
Question: Burning fuel in a furnace can?
[EX A]: kill.

[EX Q]: Fact: Hibernation is used as an important survival trait by some animals. 
Question: What is used as an important survival trait by some animals?
[EX A]:
hibernation.