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

Answer: distal.


Question: Fact: a drum has a vibrating movement. 
Question: what has vibrating movement?

Answer: drum.


Question: Fact: Clouds are one form of changing from a gas into a liquid by reducing heat energy. 
Question: What are one form of changing from a gas into a liquid by reducing heat energy?

Answer:
Clouds.