In acid rain,$SO_2$ accounts for approximately what percentage (in $, \%$)?

Reduction in soil fertility due to erosion is an example of

Assertion: Deforestation is one main factor contributing to global warming.
Reason: Besides $CO_2$,two other gases,methane $(CH_4)$ and $CFCs$,are also included under greenhouse gases.

The second commitment period for the Kyoto Protocol was decided at

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 $.....Q.....$.

$A$ - $BOD$ is a measure of the organic matter present in the water.
$R$ - The lower the $BOD$ of water,the lower is its polluting potential.