In africa, allowing livestock to feed for too long in the same area, planting on the same land over and over, and cutting down forests can all lead to a. overgrazing b. desertification c. overfarming d. deforestation

In Africa, allowing 'livestock to feed' for too long in the 'same area', planting on the 'same land over and over', and 'cutting down forests' can all lead to desertification.

Explanation:

heat from the core of the earth causes convection currents to occur in the mantle. these currents slowly move the crust around.