instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
Glycerol is a triol, an alcohol which contains three hydroxl functional groups.
answer:
Glycerol is a triol, an alcohol which contains three what?


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:
The cardiovascular system transports many substances to and from cells throughout the body.
answer:
What system transports many substances to and from cells throughout the body?