2 eroding of land by wind
4 overusing land
3 plowing land without replanting
The correct answer is that when a species is made up of different smaller groups, each of those smaller groups is known as a variety.
#19 due to weathering and erosion the rock from the stream was smoothened and without as much the rock from deep underground was/is very rugged and natural.
#18 Due to wind patterns the sand dunes are blew around and the sands shift and fly around with nothing to keep the sand in place the sand can go long distances or come long distances.
(I am back lol)
The answer to the question above is a cell.
Answer:
The reason is because it takes a long time for the light from the stars in the sky to reach earth, so the light the star was producing millions of years ago has just now reached Earth.
Hope this helped! :)