a.Explain the close fit of the west coast of Africa to the east coast of South America.?

Answer 1

The tecctonic plates moved - they once fit neatly like puzzle pieces, but have drifted in the last few million years. We know this because of early fossils from the same periods matching both coasts (and a bunch of other info that I have forgotten.)'

Look up Pangea and geology in google and you'll find everything you need.

Answer 2

In the secondary era of earth during Jurassic America and Africa were separated due to the effects of plaque tectonics. You must know that at the surface of the earth, continents and oceans lie on plaques which sometimes go together or sometimes broke away. During the Jurassic, the African plaque and south American plaque riped one from another and so Atlantic ocean begin its life