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

[Q]: Most of the gray matter is on the surface of the brain, surrounding white matter.
[A]: Most of the gray matter is on the surface of the brain, surrounding what other type of matter?

[Q]: Absorption is the process by which the substances you consume are taken up by the blood.
[A]: What is the process by which the substances you consume are taken up by the blood?

[Q]: Tides is the term for when the water of the ocean slowly rises and falls.
[A]:
What is the term for when the water of the ocean slowly rises and falls?