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: 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: Demagnetization is the process in which a magnet loses its magnetic properties.

Answer: What is the process called in which a magnet loses its magnetic properties?


Question: Air quality is a measure of pollutants in the air.

Answer:
Air quality is a measure of what in the air?