The Earth from space titled June Twenty-first. A red line is drawn horizontally through the middle of Earth. The Northern and Southern Hemispheres are labeled. Arrows toward the Earth are labeled Sun's rays. The Southern Hemisphere is tilted away from the sun. Image courtesy of Reto Stöckli (NASA)

The image above shows how the Earth receives energy on a solstice day. In this image, it's June 21. Because of the light and energy each hemisphere is receiving, which season is the Northern Hemisphere experiencing in this image?

A. winter
B. summer
C. spring
D. fall

The answer is summer. When the northern hemisphere is tilted towards the sun we are going into summer. It cannot be fall or spring because we do not have solstice days for those we have equinoxes. And it cannot be winter because the northern hemisphere would have to be pointed away for that to be the case.

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. 

The saharan africa is desert not forest