Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Q: The sun is considered the center of the solar system.

A: What is considered the center of the solar system?
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Q: Does water get colder or warmer the deeper you go?

A: Does water get colder or warmer the deeper you go?
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Q: Net primary productivity is an estimation of all of the organic matter available as food, and involves measuring biomass in terrestrial environments.

A:
What is an estimation of all of the organic matter available as food, and involves measuring biomass in terrestrial environments?
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