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: when individuals move into or out of a population, it's random. 
Question: what is it when individuals move into or out of a population?

Output: random.


Input: Consider Input: Fact: penguins are endothermic tetrapod vertebrates. 
Question: what are endothermic tetrapod vertebrates?

Output: penguins.


Input: Consider Input: Fact: Animals use the body's cells to store energy. 
Question: Animals use the body's cells to what?


Output: store energy.