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: Evolution occurs by a sorting mechanism process. 
Question: How does evolution occur?

Output: A sorting mechanism process.


Input: Consider Input: Fact: a flashlight requires a source of energy to produce light. 
Question: What requires a source of energy to produce light?

Output: flashlights.


Input: Consider Input: Fact: A battery-powered computer requires a closed circuit for electricity to flow. 
Question: A battery-powered computer requires a what for electricity to flow?


Output: closed circuit.