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

Q: Amount of salt are aquatic biomes often classified.

A: How are aquatic biomes often classified?
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Q: Particle accelerators can nuclear fusion in stars be simulated.

A: How can nuclear fusion in stars be simulated?
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Q: Ectotherms undergo a variety of changes at the cellular level to acclimatize to shifts in temperature.

A:
Ectotherms undergo a variety of changes at the cellular level to acclimatize to shifts in what?
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