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

Q: The cardiovascular system in the human body consists of the heart, a network of blood vessels, and blood.

A: Which system in the human body consists of the heart, a network of blood vessels, and blood?
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Q: Simple carbohydrates can be classified in terms of chain length.

A: Which carbohydrates can be classified in terms of chain length?
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Q: The thickness of magma determines whether a volcanic eruption will be explosive or not.

A:
What determines whether a volcanic eruption will be explosive or not?
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