Provide an explanation for europe’s projected population decrease by the year 2050.

A cultural tradition which emphasized larger families (lot's of help on a farm) has changed. As a result, fewer children are being born than in previous generations. This is likely connected to newer culture that emphasizes marrying later in life, having fewer children and options to follow career/education paths to that were not available to previous generations.

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. 

A,b,c is the answer to the question