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

Ex Input:
In the lungs, oxygen diffuses out of the alveoli and into capillaries.

Ex Output:
In the lungs, oxygen diffuses out of the alveoli and into where?


Ex Input:
10 million years long can a large star be on the main sequence stage.

Ex Output:
How long can a large star be on the main sequence stage?


Ex Input:
A basin is a three dimensional snycline.

Ex Output:

What is a three dimensional snycline?