Which process of erosion is responsible for deepening the river channel?

Verticle erosion/downcutting deepens the channel

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Answer( solar wind );

1. d: oceanic crust is thicker and contains a lot of granite2.d: where two continental plates are colliding  3.b.contour boundaries4.b.plates that are attracted to each other by gravity5.a.as two continental plates collide along a convergent boundary, mountains are formed.