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.

Fact: A compass is used to find magnetic north. 
Question: What does a compass find?
magnetic north.

Fact: an automobile engine transforms chemical energy into sound. 
Question: an automobile engine cn transforms chemical energy into?
sound.

Fact: engines transform chemical energy into mechanical energy and have a range where they are efficient. 
Question: The efficiency of an engine range is due to what?

chemical to mechanical energy.