Question

practice 2
which of the following is an example of erosion in action?
rock on the edge of a river
soil material being moved downstream by water
a tree growing next to a lake
a desert valley

Explanation:

Erosion is the process of soil, rock, and other surface - material movement by natural forces like water, wind, etc. Soil material being moved downstream by water is a clear example of water - induced erosion. A rock on the edge of a river just being there isn't erosion in action, a tree growing next to a lake is a biological process not erosion, and a desert valley is a landform not an example of the process of erosion in action.

Answer:

soil material being moved downstream by water