instruction:
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.
question:
Fact: ears are used for hearing. 
Question: What are ears used for?
answer:
to hear.


question:
Fact: Bacteria in soil coverts atmospheric nitrogen into a form usable by flowers. 
Question: What converts nitrogen for flowers?
answer:
bacteria.


question:
Fact: astronauts require preserved food for space. 
Question: What requires preserved food for space?
answer:

astronauts.