At the equator, the sun is directly overhead at noon on these two equinoxes. the nearly equal hours of day and night is due to the refraction of sunlight or bending of lights Ray's that causes the sun to appear above the horizon when the actual position of sun is below the horizon.
Not quite sure what you're asking, but erosion and deposition do create land forms. For example: erosion along the coastline may result in the formations of arches, stacks, stumps, wave cut platforms, caves, etc. Deposition, different amount of it and in certain areas, under the influence of either destructive or constructive waves, will form beaches - ones with a lot of beach, through a lot of deposition, or slopes beaches where destructive waves have crashed upon the beach. Hope this is what you're looking for.
C. -1,0. I hope I helped!
Answer: United States
Hope this helps :$
