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.

Input: Consider Input: Fact: Populations of the cause of influenza do not grow through cell division because they are not cells. 
Question: The cause of what doesn't grow by cell division?

Output: Influenza.


Input: Consider Input: Fact: waves can be used to produce electricity. 
Question: What can be used to produce electricity?

Output: waves.


Input: Consider Input: Fact: microbial control agents may spread directly from one person to another. 
Question: what may spread directly from one person to another?


Output: microbial control agents.