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: bears hibernate to conserve energy. 
Question: Why do bears hibernate?

Output: conserve energy.


Input: Consider Input: Fact: A fertilized egg can create an offspring if it's carried until birth. 
Question: When does a fertilized egg become an offspring?

Output: When it's born.


Input: Consider Input: Fact: temperature can change the state of matter. 
Question: What can change the state of matter?


Output: temperature.