What caused the interior of earth to separate into layers? a.  a decrease in the rate of rotation of earth b.  the gravitational pull on materials of varying densities c.  variations in heating by the sun due to earth's tilt d.  collisions with meteors and comets?

While viewing a topographic map, you notice a region in which the contour lines are very close together. what can you conclude about this region? a. it has a high population. b. it has a steep incline. c. it's near a political boundary. d. it contains a body of water.