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

Ex Input:
The male reproductive system consists of structures that produce sperm and secrete testosterone.

Ex Output:
What does the male reproductive system consist of?


Ex Input:
The action of flushing the toilet, performed multiple times daily, is the single biggest use of water in the home.

Ex Output:
What action, performed multiple times daily, is the single biggest use of water in the home?


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?