instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
While the numerical aperture can be used to compare resolutions of various objectives, it does not indicate how far the lens could be from the specimen.
answer:
While the numerical aperture can be used to compare resolutions of various objectives, it does not indicate how far the lens could be from the what?

question:
Gravity makes soil and rock particles move gradually down the slope during each thaw.
answer:
What makes soil and rock particles move gradually down the slope during each thaw?

question:
Living things on the ocean floor are known as benthos.
answer:
Living things on the ocean floor are known as?