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: A protein-rich fluid leaks into spaces between cells. 
Question: A protein-rich what leaks into spaces between cells?
Example Output: fluid.

Example Input: Fact: Food can be cooked on metal. 
Question: Which surface can food be cooked on?
Example Output: Metal.

Example Input: Fact: A porcupine will extend its quills when intimidated. 
Question: What defense mechanism does a porcupine use when intimidated?
Example Output:
quills.