1. which of the following statements about vietnam is true? a. hanoi is the main center of vietnam's marketplace economy. b. vietnamese farmers have long specialized in the production of arabica coffee. c. vietnam's current level of rice exports challenges that of india. d. vietnam is no longer a communist country.

The Vietnam's current level of rice exports challenges that of India.

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. 

Increasing the release of greenhouse gases and pollution