The European union can be called C) a federation.
D. They depict many different subjects, using bright colors and patterns.
Hope it helps :) sorry if I am wrong :(
In 1960 BCC this happened
The early atmosphere on Earth was mostly carbon dioxide.
It was also poisonous and extremely hot.
Atmosphere is the gaseous envelope of a planet.
Today's atmospheric functions include sustaining life with oxygen, produced from plants; filtering harmful rays from the sun, helping in protecting the Earth from meteor collisions.
