What are the convection currents, and how do they affect the earth's asthenosphere

In africa what do they call a crop grown for direct sale and not for use?

Cutting and burning the skin are two examples of

Which statement explains what similar fossils found on distant continents suggest about earth’s history? animals have evolved over time. the continents have moved over time. earth’s oceans had varying salt content through time. there have been many animals on earth that are now extinct.