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.

Example Input: Fact: Viruses often infect something killed by antibiotics. 
Question: Viruses often infect something killed by what?
Example Output: Antibiotics.

Example Input: Fact: Mammals took advantage of an asteroid impact. 
Question: What took advantage of an asteroid impact?
Example Output: mammals.

Example Input: Fact: A bill is used for catching prey by some birds. 
Question: What is used by some birds to catch their prey?
Example Output:
a bill.