A measuring cup is used for measuring the volume of substances.
For any substance, the density is a measure of the mass of a unit volume of that substance.
A measuring cup is used for measuring the density of a substance.
a measuring cup is used for measuring the what?

1: sound of water
2: thickness of food
3: density of substances
4: Temperature
5: all liquids
6: creaminess of texture
7: objects that have mass
8: air mass over Earth's surface