1. when a mass of material moves downslope under the influence of gravity, the process is called: a. mass wasting b. rockslide c. slump d. mudflow
2. only a tiny fraction of earth’s water is drinkable by humans. a. true b. false
3. which of the mass movements listed below is the fastest? a. mudflows b. soil creep c. avalanche d. earthflow

1- Option (A)

              2- True

              3- Option (C)

Explanation: Mass wasting refers to the phenomenon in which the materials after weathering, falls down along a slope due to the action of gravity.

On earth, there is about 70% of water and land covers about 30%. Again, out of this 70% of total water, there is only 2-3% which is the fresh water, all the remaining water are the saline water. So, this amount is significantly less, therefore, a very few amount of water is present on earth which can be used for drinking purpose. Hence, the statement is true.

The debris avalanche is the fastest of all the mass wasting types, as the rocks and debris here falls very rapidly at a huge speed, under the action of gravity.