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

Momentum is directly related to both mass and velocity.
Momentum is directly related to both mass and?

A hookworm is classified as a parasite.
A hookworm is classified as what type of organism?

Carbon atoms have six neutrons as well as six protons.

Carbon atoms have six neutrons as well as how many protons?