Answer:
the answer is PP
hope it is right
how does a glacier, at its base and sides, modify a bedrock valley?
Answer:
They can erode bedrock by two different processes: Abrasion: The ice at the bottom of a glacier is not clean but usually has bits of rock, sediment, and debris. It is rough, like sandpaper. As a glacier flows downslope, it drags the rock, sediment, and debris in its basal ice over the bedrock beneath it, grinding it