Given a scientific question, generate a correct answer to it.

[EX Q]: What phenomenon makes global winds blow northeast to southwest or the reverse in the northern hemisphere and northwest to southeast or the reverse in the southern hemisphere?
[EX A]: coriolis effect

[EX Q]: What is indicated by the ratio of the output force to the input force in a machine?
[EX A]: mechanical advantage

[EX Q]: 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?
[EX A]:
specimen