Answer:
对不起兄弟我不知道我需要增加什么什么什么什么??????Duìbùqǐ,
A
Less than 5% make a living through agriculture
Because it is important to know the composition of the object
Density is the ratio of the mass of a sample to the volume occupied by that mass, and expresses how much mass there is per unit volume of a given portion of matter. Density is a physical property of extreme importance in the characterization, identification and use of substances or materials.