Select the correct statement regarding conventional chemical farming methods.

Match the items given in column $A$ and $B$:

Column $A$	Column $B$
$(a)$ Catalytic converter	$(i)$ Particulate matter
$(b)$ Electrostatic precipitator	$(ii)$ Carbon monoxide and nitrogen oxides
$(c)$ Earmuffs	$(iii)$ High noise level
$(d)$ Landfills	$(iv)$ Solid wastes

Which of the following is a pollution-related disease?

How many sentences are correct?
$(1)$ $CNG$ burns most efficiently.
$(2)$ $CNG$ cannot be adulterated.
$(3)$ $CNG$ is cheaper than petrol and diesel.
$(4)$ In the $1990$s,Delhi ranked $4$th among the $41$ most polluted cities of the world.

In a pond near a village,a large number of fish suddenly die. Which of the following could be the reason for this?
$(a)$ Large amounts of urea and phosphate are used as fertilizers in nearby fields.
$(b)$ $DDT$ was sprayed in the entire area.
$(c)$ The pond water has become green and dirty.
$(d)$ The population of phytoplankton in the pond has decreased,reducing the photosynthetic capacity.
Which two of the above reasons are responsible?

Aerosols reduce primary productivity by