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: A cactus stem is used for storing H20. 
Question: A cactus stem is used for storing what?

Output: H20.


Input: Consider Input: Fact: melting means changing from a solid into a liquid by increasing temperature. 
Question: what is increased to cause something to change from a solid into a liquid?

Output: temperature.


Input: Consider Input: Fact: budding and fusion of vesicles in the Golgi complex involves energy, so it is active. 
Question: budding and fusion of vesicles in the Golgi complex involves what?


Output: energy.