Recently, due to rapid urbanization and mechanization residents of a city are suffering from harmful effects of the ultra violet rays. Depletion of which layer is likely to have led to this situation? A. oxygen B. carbon dioxide C. nitrogen D. ozone E. methane

D

Explanation:

The correct answer would be ozone.

Only the depletion of the ozone layer can increase the amount of ultraviolet rays in the atmosphere thereby causing harmful effects to the residents. The ozone layer originally forms a shield that filters off ultraviolet rays from the radiation coming from the sun. By doing so, the ultraviolet ray that gets to the earth is minute and biological organisms are thus insulated from the harmful effects of the ray.

The ozone layer is gradually depleted by pollutants such as CFC which is released into the atmosphere by the actions of man. As urbanization and mechanization increase, more and more of these ozone degrading pollutants are released leading to a rapid depletion of the ozone layer.

The correct option is D.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.