Read the following paragraph and answer the question. Give ONLY the answer, no other words or explanation.

For example:

Answer: <most likely answer, as short as possible>.

Paragraph: 
Volume is another way of measuring material. Gases cannot be easily weighed, but their volume can be determined quickly and accurately. Liquid chemicals as well as foods and beverages are also sold by volume. Gasoline for our cars and trucks is sold by the gallon. At the grocery store, we can buy a gallon of milk or a two-liter bottle of soda pop.


Question: Volume is another way of measuring what?
material
Material.