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

Q: Most have cells that are not able to exchange gases with the outside environment do multicellular organisms need transport systems.

A: Why do multicellular organisms need transport systems?
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Q: Absorption is the process by which the substances you consume are taken up by the blood.

A: What is the process by which the substances you consume are taken up by the blood?
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Q: Three many pathways do plants have for carbon fixation.

A:
How many pathways do plants have for carbon fixation?
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