Water, wind, ice, and waves are the agents of erosion that wear away at the surface of the earth.
(Water, wind, ice, and waves; are; the agents of erosion that wear away at the surface of the earth) (the agents of erosion; wear; away; L:at the surface of the earth)
Water, wind, ice, and waves the agents of erosion
are wear
the agents of erosion that wear away at the surface of the earth
away L:at the surface of the earth