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.

Input: Consider Input: Fact: air is required for breathing. 
Question: What is required for breathing?

Output: air.


Input: Consider Input: Fact: animals use glucose for energy. 
Question: what do animals use for energy?

Output: glucose.


Input: Consider Input: Fact: shellfish have a circulatory system with one or two hearts that pump blood. 
Question: shellfish have a circulatory system with one or two hearts that pump what?


Output: blood.