There are 50 states in the US
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.
You have to find what the letter stands for in an equation
The correct answer is Ravenna.
That is because Ravenna was a city that was reconquered by the Byzantine empire after it originally fell to the Ostrogoth when the fall of the Western Roman Empire occurred. It was a capital for western Romans and for the Ostrogoth, but it wasn't for the Byzantine people who had their own capitol even after they reconquered it.
