Question

How did the mountains, plains, seas and oceans formed

Answer 1

mountain, plains are from by weathering and the rest by melting of ice

Answer 2

When the river sediments build up enough, they can rise above sea level. Combined with runoff from hills andmountains, these sediments formcoastal plains. Abyssal plains form on the ocean floor when sediments and ooze settle and accumulate on the bottom of the ocean over long periods of time.