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: space exploration is not possible without navigation. 
Question: What is used for space exploration?
navigation.

Fact: Diabetes is caused by a reduction of a hormone that helps cells absorb sugar from the blood. 
Question: What is caused by a reduction of a hormone that helps cells absorb sugar from the blood?
diabetes.

Fact: Most fish do not have to deal with extremes of temperature or moisture. 
Question: Most _ do not have to deal with extremes of temperature or moisture.?

fish.