4. Photographs A and B below show two different valleys. Photograph A
Photograph B
Which list best identifies the agent of erosion that primarily determined the shape of each valley?
A) photograph A-glacier, photograph B-river
B) photograph A-river, photograph B-glacier
C) both photographs-river
D) both photographs-glaciel

depends where

on my head

yes

on my legs

yes

on my

arms

yesh

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.