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.

Example Input: Fact: The volume of an object can be used to measure the mass of the object. 
Question: The volume of an object can be used to measure what?
Example Output: the mass of the object.

Example Input: Fact: boulders are formed by snow, ice, and rock melting sometimes. 
Question: what melts sometimes to form boulders?
Example Output: snow, ice, and rock.

Example Input: Fact: whiskers are used for feeling by cats. 
Question: what uses whiskers for feeling?
Example Output:
cats.