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: Toyota causes pollution. 
Question: What causes pollution?
[EX A]: Toyota.

[EX Q]: Fact: deoxyribonucleic acid replication is the process in which it is copied. 
Question: what is copied during the process of replication?
[EX A]: deoxyribonucleic acid.

[EX Q]: Fact: detailed observation of celestial objects requires light. 
Question: To make detailed observations of celestial objects requires what?
[EX A]:
light.