A city is a functional region
I attached a picture of the layers of the earth. They are the:
Crust (<em>which isn't really the interior</em>)
Mantle
Outer Core
Inner Core
Answer:
In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. A crystal structure is composed of a unit cell, a set of atoms arranged in a particular way; which is periodically repeated in three dimensions on a lattice.
Explanation: