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

Q: Pyramid ecosystem is used to show energy flow through the trophic levels.

A: What is used to show energy flow through the trophic levels?
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Q: The ileocecal valve, a sphincter, is usually in a constricted state, but when motility in the ileum increases, this sphincter relaxes, allowing food residue to enter the first portion of large intestine.

A: The ileocecal valve, a sphincter, is usually in a constricted state, but when motility in the ileum increases, this sphincter relaxes, allowing food residue to enter the first portion of what?
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Q: A statement that describes what always happens under certain conditions in nature is also known as scientific law.

A:
A statement that describes what always happens under certain conditions in nature is also known as what?
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