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

[EX Q]: When the smooth muscle relaxes, the arterioles dilate, allowing blood to enter the capillaries.
[EX A]: When the smooth muscle relaxes, the arterioles dilate, allowing blood to enter the what?

[EX Q]: 40 m/s north of the following represents the velocity of a moving object.
[EX A]: Which of the following represents the velocity of a moving object?

[EX Q]: To determine the atomic weight of an element, you should add up protons and neutrons.
[EX A]:
How do you determine the atomic weight of an element?