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: oxygen is essential for cellular respiration for fungi. 
Question: what requires oxygen for cellular respiration?

Output: fungi.


Input: Consider Input: Fact: Chromosomes are units of information causing traits to be passed down to offspring. 
Question: Chromosomes are units of information causing traits to be what to offspring?

Output: passed down.


Input: Consider Input: Fact: using an engine requires burning flammable liquid. 
Question: using an what requires burning flammable liquid?


Output: engine.