Glacial erosion: Glaciers are arguably the most effective erosion agents operating on the surface of the Earth, and therefore play important roles in shaping mountain ranges and creating the characteristic features of alpine landscapes such as hanging valleys and overdeepenings.
(Glaciers; are arguably; the most effective erosion agents operating on the surface of the Earth) (the most effective erosion agents; operating; L:on the surface of the Earth)
Glaciers the most effective erosion agents
are arguably operating
the most effective erosion agents operating on the surface of the Earth
L:on the surface of the Earth