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

Group 16 is called the oxygen group.
Group 16 is called what?

The long bone work as lever.
What type of function does the long bone perform?

The human penis contains the urethra, as well as three cylinders of spongy erectile tissue.

The human penis contains the urethra, as well as how many cylinders of spongy erectile tissue?