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.

[Q]: Fact: Bacteria can cause food to spoil. 
Question: What causes food to spoil?
[A]: Bacteria.


[Q]: Fact: Most animals without backbones have a nervous system. 
Question: Which type of system do most animals without backbones have?
[A]: Nervous system.


[Q]: Fact: an animal needs to attract a mate for sex. 
Question: What does an animal need to attract a mate for?
[A]:
sex.