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: Nails prevent injury by forming protective plates over distal ends. 
Question: Nails prevent injury by forming protective plates over what ends?

Output: distal.


Input: Consider Input: Fact: When heat passes through metal, that metal expands. 
Question: What happens to metal when heat passes through it?

Output: It expands.


Input: Consider Input: Fact: Rocks that are formed by deposition are then eroded to form a new generation. 
Question: Rocks that are formed by deposition are then what to form a new generation?


Output: eroded.