Answer:
7) The Cretaceous period and it lasted for 80 million years
8) The Cenozoic era for 65 million years
9) 4.5 billion years ago
10) It began 252.2 million years ago
11) It ended 66 million years ago
12) About 190 million years
Explanation:
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B. Colonialism
I'm not sure But, Please correct me if I'm wrong!!
Answer:
78 percent - nitrogen
21percent- oxygen
absorbs ultraviolet-ozonosphere
atmospheric weather-stratosphere
starts seven miles -troposphere
layer composed 0f layers- thermosphere
important fr radio wave-ionosphrere
trapping of heat- green house effect