Ghana, Mali, and Songhai were A. large oases in the Sahara.
B. poor countries in coastal West Africa.
C. important leaders in Central Africa.
D. ancient empires in the Sahel.

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

Solve for r in the formula v = ir, when i = 5 and v = 15.

An enormous wave generated by an earthquake beneath the seafloor is known as a