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: The crystallized rocks are made by lava from the mantle. 
Question: Where does the lava come from that makes igneous rocks?
answer:
Mantle.


question:
Fact: The mass of the Earth helps cause flowing rivers. 
Question: Which aspect of the Earth is needed to have flowing rivers?
answer:
Mass.


question:
Fact: being near the sun can cause an object to combust. 
Question: What can being near the sun do to an object?
answer:

combust it.


