Mots Croisés Earth's Outer LayersVersion en ligne Earth is made of layers. Since Earth is round, the layers all have the ending "-sphere" par Rosa Andica 1 All the water on Earth. 2 The thin layer of air, mostly nitrogen and oxygen, that surrounds the Earth. 3 The solid rock part of Earth, including mountains, valleys, continents, and all of the rock beneath the oceans. 4 All the living organisms on Earth. 4 2 1 3