==> the object's mass; ==> how close you can get to its center.
<span>Erosion by rivers is a main valley-forming
process; other processes, such as movement of the earth's crust and
glaciers, also have an important part in some cases. The rate at which a
river deepens its valley depends on several factors.</span>
Answer: A. the mid-ocean ridges
Explanation:
The features that form the longest mountain range on Earth is the mid-ocean ridges and spans about 40,389 miles around the earth.
The mid-ocean ridge has about 90% of its system under the ocean. They are formed as a result of the movement of tectonic plates.
