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.

[Q]: Fact: Eggs are fertilized during reproduction. 
Question: What happens during reproduction?
[A]: eggs are fertilized.


[Q]: Fact: An automobile engine works by summing kinetic energy and potential energy. 
Question: What works by summing kinetic energy and potential energy?
[A]: an automobile engine.


[Q]: Fact: lungs are used for breathing air by elephants. 
Question: What uses lungs for breathing air?
[A]:
elephants.