Soil conservation can be best achieved by having

At the beginning of the $20^{th}$ century,forests covered about $.....P.....$ of the land in India. By the end of the century,this had shrunk to $.....Q.....$.

Match the items in Column $A$ with those in Column $B$:
\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau\tau

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 waste

Snow-blindness in the Antarctic region is due to

Rice fields produce an important greenhouse gas. Name it.

The most common pesticide used in India is