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

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

[EX Q]: As a myotube is formed from many different myoblast cells, it contains many nuclei, but has a continuous cytoplasm.
[EX A]: As a myotube is formed from many different myoblast cells, it contains many nuclei, but has a continuous what?

[EX Q]: Tar sands are rocky materials mixed with very thick oil.
[EX A]:
Tar sands are rocky materials mixed with what?