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: The cause of smallpox is usually thought to be nonliving. 
Question: Many believe the cause of smallpox to be what?

A: Nonliving.
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Q: Fact: rivers can slowly dissolve carbon in sedimentary rock. 
Question: what can slowly dissolve carbon in sedimentary rock?

A: rivers.
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Q: Fact: when the seasons change from the summer to the fall, the days become colder. 
Question: when the seasons change from the summer to the fall, the days become what?

A:
colder.
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