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: Limestone is insoluble in water, so acid can dissolve it.

Answer: Limestone is insoluble in water, so what can dissolve it?


Question: Water can be boiled to kill giardia and most other pathogens.

Answer: Water can be boiled to kill giardia and most other what?


Question: You call the hard case that surrounds the soft parts of some animals the exoskeleton.

Answer:
What do you call the hard case that surrounds the soft parts of some animals?