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: Amphibians have a larynx to make sounds. 
Question: What do amphibians use to make sounds?

A: Voice box.
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Q: Fact: The mass of the Earth helps cause flowing rivers. 
Question: Which aspect of the Earth is needed to have flowing rivers?

A: Mass.
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Q: Fact: An image in a reflection is formed by light bouncing off of a surface. 
Question: What causes an image to reflect?

A:
Light.
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