A.) Clear new areas of land after a few years
Hope it helps!
Erosion is the process by which the surface of the Earth gets worn down. Erosion can be caused by natural elements such as wind and glacial ice. But anyone who has ever seen a picture of the Grand Canyon knows that nothing beats the slow steady movement of water when it comes to changing the Earth.
You need to add x1 and x2 then divide by two, then add y1 and y2
Humans do not contribute to the change of seasons
