Green house effect is caused by

Increased concentration of Co₂ in atmosphere is responsible for

The harmful constituent present in air are called

The smog is essentially cared by the presence of

Automobiles can reduce the carbon monoxide and other pollutant by the installation of

The region closest to earth surface is

A catalyst used in the preparation of oxygen from H₂O₂ is

To remove particulate matter from the air emitted by thermal power station which of the precipitation is used