Earth is composed of four main layers, starting with an inner core at the planet's center, enveloped by the outer core, mantle, and crust. The inner core is a solid sphere made of iron and nickel metals about 759 miles (1,221 kilometers) in radius.
source: nasa
While race<span> and </span>ethnicity<span> share an ideology of common ancestry, they differ in several ways. First of all, </span>race<span> is primarily unitary. You can only have one </span>race<span>, while you can claim multiple </span>ethnic<span> affiliations. You can identify ethnically as Irish and Polish, but you have to be essentially either black or white.</span>
Physical maps show different geographical features, bodies of water, and land forms.