instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
Molar masses can be used to determine the mass of a quantity of material.
answer:
What can be used to determine the mass of a quantity of material?

question:
Sodium-potassium pumps help nerve cells establish a voltage across their plasma membranes.
answer:
Sodium-potassium pumps help nerve cells establish a voltage across their what?

question:
Humans create different breeds of organisms using artificial selection.
answer:
Humans create different breeds of organisms using what kind of selection?