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: plants are sensitive to darkness. 
Question: What are plants sensitive to?

A: darkness.
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Q: Fact: small capillaries collect fluid. 
Question: What collects fluid?

A: small capillaries.
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Q: Fact: Something that is primarily electrostatic in origin causes water to expand when it freezes. 
Question: Something that is primarily electrostatic in origin causes water to expand when it what?

A:
freezes.
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