Why are the troposphere and the stratosphere important to human survival?

Soweto was the site of one of the that swept across south africa in the late 1970s. in his effort to end apartheid, desmond tutu turned to . the united states responded to south africa’s apartheid policy in the 1980s by .

Impressions of tropical swamp plants were observed on rocks in polar regions. the impressions were dark black imprints, which means the fossils are examples of ( 1 ) the fossils tell us that polar regions ( 2 ) ( 1 ) a. carbonization b. mineralization c. trace fossils ( 2 ) a. had tropical plants that can grow in ice b. might have had a diffierent climate in the past c. will have abundent vegitation

Can someone me? i need to have this done as soon as possible! i'm putting 20 points on this!