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: cell division is how humans grow and repair themselves. 
Question: what uses cell division to grow and repair themselves?
answer:
humans.


question:
Fact: Turbines are used to producing electricity. 
Question: turbines are used to what?
answer:
produce electricity.


question:
Fact: Roundworms make important contributions to soils. 
Question: Where are roundworms useful in an ecosystem?
answer:

soils.