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: Bees are naturalized on every continent except antarctica.

Answer: Bees are naturalized on every continent except which?


Question: Monatomic ions form when a single atom gains or loses electrons.

Answer: What form when a single atom gains or loses electrons?


Question: In the freshwater flatworms, protonephridia serve chiefly in osmoregulation.

Answer:
In the freshwater flatworms, protonephridia serve chiefly in what?