The ice and rock carried by these glaciers acted as sandpaper in moving down the valley, smoothing and widening them, leaving U -shaped profiles for the valley cross-sections.
(The ice and rock; carried; by these glaciers) (The ice and rock carried by these glaciers; acted; as sandpaper in moving down the valley, smoothing and widening them, leaving U -shaped profiles for the valley cross-sections)
The ice and rock The ice and rock carried by these glaciers
carried acted
by these glaciers
as sandpaper in moving down the valley, smoothing and widening them, leaving U -shaped profiles for the valley cross-sections