(i) The removal and transportation of the top layer of soil from its original position to another place, under the effect of strong winds and fast running rain water is called soil erosion.
It can be prevented by planting trees and grasses. Proper drainage canals around the fields can prevent soil erosion.
(ii) Nucleic acid and proteins.
(iii) Water is essential for life due to following reasons
(a) All cellular processes take place in water medium.
(b) Water is required for salt and electrolytes maintenance inside the body.