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: warblers are nocturnal and travel long distances at night. 
Question: What are nocturnal and travel long distances at night?

A: warblers.
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Q: Fact: Viruses often infect something killed by antibiotics. 
Question: Viruses often infect something killed by what?

A: Antibiotics.
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Q: Fact: friction is used for stopping by trucks and cars using brakes. 
Question: what uses friction to stop using brakes?

A:
trucks and cars.
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