What do an ogre, an onion and the earth have in common? they have layers! how many layers does the earth have?

The earth has layers and is composed of four layers. The four layers of the earth are namely, crust, mantle, the outer core and the inner core. The core in the layers of the earth serves as the central region. The mantle is the earth’s solid bulk in terms of its interior. The inner and outer core are composed minerals and are the third and fourth layer in the earth.

i'm guessing this is from edg enuity so the answers would be, from top to bottom,

theodor schwann

matthias schleiden

robert hooke

rudolph virchow

anton van leeuwenhoek

oxygen = 21% of the atmosphere

nitrogen = 78%

carbon dioxide = 0.1%

argon =0.934%