Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
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Question: Antibodies recognize and combine with harmful materials, including both toxic chemicals and invasive microorganisms.

Answer: Which proteins recognize and combine with harmful materials, including both toxic chemicals and invasive microorganisms?


Question: Invertebrates (and higher animals) can also be placed in one of two groups based on how they develop as embryos.

Answer: Invertebrates (and higher animals) can also be placed in one of two groups based on how they develop as what?


Question: The precapillary sphincters regulate(s) the passage of blood into capillary beds.

Answer:
What regulates the passage of blood into capillary beds?