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: claws are used to catch arthropods by some predators. 
Question: what do predators use claws to catch?
Example Output: arthropods.

Example Input: Fact: You can navigate through the Pacific with a compass. 
Question: What can you use to navigate the Pacific?
Example Output: compass.

Example Input: Fact: some nerve endings sense differences in temperature. 
Question: What senses differences in temperature?
Example Output:
nerve endings.