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: Food can be cooked on metal. 
Question: Which surface can food be cooked on?

Answer: Metal.


Question: Fact: animals with calcite shells form large colonies in shallow tropical water. 
Question: Animals with _ form large colonies in shallow tropical water?

Answer: calcite shells.


Question: Fact: If Mars becomes too hot then Mars cannot sustain life. 
Question: What happens if Mars becomes too hot?

Answer:
it cannot sustain life.