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

[EX Q]: Poles parts of the planet does solar energy have difficulty reaching.
[EX A]: What parts of the planet does solar energy have difficulty reaching?

[EX Q]: Chemical digestion mainly occurs in the small intestine.
[EX A]: Where does chemical digestion mainly occur?

[EX Q]: Pressure is defined in physics as the amount of force pushing against a given area.
[EX A]:
What is defined in physics as the amount of force pushing against a given area?