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

Q: Temperature and ph level are important in the activity of an enzyme.

A: Temperature and what other environmental factor are important in the activity of an enzyme?
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Q: Light retains its original color under water because frequency remains the same when light is refracted.

A: Light retains its original color under water because what remains the same when light is refracted?
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Q: Closest to the nucleus orbitals do electrons fill first.

A:
Which orbitals do electrons fill first?
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