What is masswasting. ?.
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Mass wasting, also known as slope movement or mass movement, is the geomorphic process by which soil, sand, regolith, and rock move downslope typically as a solid, continuous or discontinuous mass, largely under the force of gravity, frequently with characteristics of a flow as in debris flows and mudflows

Explanation:

Thats what wikipedia said

doctrine that the us had the right to expand throughout north america.