The cause of decline in the population of reptiles and birds is

The Bhopal gas tragedy in $1984$ was caused by the leakage of which gas?

Thermal power plants,smelters,metal refineries,and other industries release $................$ pollutants.

In agriculture,improper drainage of water leads to:
$I-$ The soil becomes waterlogged.
$II -$ The soil surface draws up salts from the water.
$III -$ Salts are deposited as a thin crust on the land surface.
$IV -$ Salts start accumulating around the roots of the plants.
$V -$ The increasing concentration of salts becomes favorable for crop growth.
$VI -$ It is highly beneficial for agriculture.
Which of the above statements are correct?

$A$ lake which is rich in organic waste may result in

An electrostatic precipitator is used in thermal power plants to remove $...........$ from the exhaust gases.