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

[EX Q]: Gastric emptying is regulated by both the stomach and the duodenum.
[EX A]: Gastric emptying is regulated by both the stomach and what other digestive structure?

[EX Q]: Thermosphere is the upper-most atmosphere.
[EX A]: What is the upper-most atmosphere known as?

[EX Q]: Exposure to ultraviolet radiation can increase the amount of pigment in the skin and make it appear darker.
[EX A]:
Exposure to what can increase the amount of pigment in the skin and make it appear darker?