As developing nations industrialize and make use of capital resources, new challenges to the supply of the world's natural resources will no doubt appear because- A. the newly developed countries will industry overtake the existing developed countries
B. the rate of depletion will increase as developing countries begin to use more natural resources
C. more developed countries do not want developing countries to become more economically independent
D. the developing countries will learn to bargain with their natural resources impact the economies of other nations

Mantle convection is the process that drives plate tectonics. the theory of plate tectonics states that the crust is divided into plates that float on the semi molten mantle below. the circular motion of the magma as it slowly rises and falls or move though convection cells drags the plates along causing them to move. the heat source in the lamp would represent the earth's core. the core is the source of energy that drives convection in the mantle. the lava represents molten magma under the earth's surface. if the lava lamp had floating pieces they would move as the circular motion of the lava in the lamp as it rises and falls would move them along the surface. these floating pieces would represent pieces of the earth's crust. 

Its decreasing because of illnesses