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.

[EX Q]: Fact: Mutations can be detected by analysis on gene abnormalities. 
Question: Which process of gene abnormalities can mutations be detected?
[EX A]: analysis.

[EX Q]: Fact: Axons transmit brain impulses to other cells. 
Question: What transmits brain impulses to other cells?
[EX A]: Axons.

[EX Q]: Fact: limestone contains carbon. 
Question: what is in limestone?
[EX A]:
carbon.