Question: A *** on top of a *** is *** at 30 *** *** in 1957. *** years later, in 2007, the *** is *** again and is now 21 *** high. What *** best *** the *** for the rock's *** in ***?  (A) weathering (B) wind erosion (C) water erosion (D) chemical erosio.
E.