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


question:
Fact: A vehicle in use requires navigation. 
Question: A vehicle in use requires?
answer:
navigation.


question:
Fact: when bats fly, chemical energy is converted to mechanical energy. 
Question: When is chemical energy converted to mechanical energy?
answer:

when bats fly.