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


question:
Fact: Blood in our body contains minerals. 
Question: what in our body contains minerals?
answer:
blood.


question:
Fact: local anesthetics block electrical signals. 
Question: what does local anesthetics block?
answer:

electrical signals.