What process can remove part of a mountain?

Distance that lewis and clark traveled from st. louis to ft. clatsop near the pacific ocean.

Canada plays an important role in the global community in all of the following ways except by a. acting as a superpower with influence over europe and asia. b. promoting arms control and disarmament. c. working with the commonwealth of nations to promote trade. d. promoting trade with japan and other asian countries.

Can someone me with this plz? ! i'm putting 20 points on it!