How do you spell the word "the"

What is the importantence of the carbon and nitretan cycles in the environment

The earths core is made up mainly of what 2 substances? 2. like an egg, earth has a core, a layer surrounding the core, and a thin, hard outer layer. which layers of the earth match the layers of an egg?

Adistinctive characteristic of mammals that is not observed in other vertebrates is