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: Plants are essential for cellular respiration for all aerobic organisms. 
Question: What is essential for cellular respiration for all aerobic organisms.?

Output: Plants.


Input: Consider Input: Fact: moist air falls on the windward side of a mountain. 
Question: Where does moist air fall on a mountain?

Output: windward side.


Input: Consider Input: Fact: Oxygen acts as an aid to a car engine converting gasoline into motion and heat. 
Question: What acts as an aid to a car engine converting gasoline into motion and heat?


Output: oxygen.