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

Q: Most protein antigens require signals from helper t cells (th2) to proceed to make antibody.

A: Most protein antigens require signals from helper t cells (th2) to proceed to make what?
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Q: The combustion of propane gas produces carbon dioxide and water vapor.

A: The combustion of propane gas produces carbon dioxide and what else?
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Q: Multiple fission is more often observed among protists.

A:
Where is multiple fission more often observed?
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