What damage does vegetation cause?

The per capita forest area in India is ......... (in $ha$)

Consider the following reasons for the massive fish mortality observed in a lake near a village within a few days:
$(1)$ Excessive use of urea and phosphate fertilizers in nearby crops.
$(2)$ Spraying of $DDT$ using aircraft.
$(3)$ The lake water turned green and foul-smelling.
$(4)$ Initial decrease in phytoplankton in the lake leads to a maximum decrease in photosynthesis.
Which of the above reasons are responsible for the massive fish mortality?

Select the correct statement regarding conventional chemical farming methods.

River water deposits which of the following types of soil?

Domestic sewage mainly contains $A$ wastes which are readily decomposed with the help of $B$. Here $A$ and $B$ refer to: