Some statements are given:
$(S_1) \ CO_2$ is a greenhouse gas.
$(S_2)$ Classical smog contains smoke,fog,and a high concentration of $SO_2$.
$(S_3) \ DDT$ is biodegradable.
$(S_4)$ Drinking water should have a high $B.O.D.$
Which is the correct sequence of true $(T)$ or false $(F)$ regarding the above statements?

What steps should be taken to reduce the production of acid rain?

Name the pollutants found in the troposphere.

From the following,identify the reactions which are responsible for the depletion of the ozone layer.
$I. Cl\dot{O}_{(g)} + NO_{2_{(g)}} \rightarrow ClONO_{2_{(g)}}$
$II. CF_2Cl_{2_{(g)}} \xrightarrow{uv} \dot{Cl}_{(g)} + \dot{CF}_2Cl_{(g)}$
$III. \dot{Cl}_{(g)} + CH_{4_{(g)}} \rightarrow HCl_{(g)} + \dot{C}H_{3_{(g)}}$
$IV. \dot{Cl}_{(g)} + O_{3_{(g)}} \rightarrow Cl\dot{O}_{(g)} + O_{2_{(g)}}$
$V. Cl\dot{O}_{(g)} + O_{(g)} \rightarrow \dot{Cl}_{(g)} + O_{2_{(g)}}$

Match the pollutant in List-$I$ with its maximum permissible limit in drinking water given in List-$II$.

List-$I$	List-$II$
$(A)$ Lead	$(I)$ $500 \text{ ppm}$
$(B)$ Sulphate	$(II)$ $50 \text{ ppm}$
$(C)$ Nitrate	$(III)$ $50 \text{ ppb}$

Observe the following statements:
Statement-$I$: The carbon-containing components of photochemical smog are acrolein,methanal,and $PAN$.
Statement-$II$: The number of greenhouse gases in the list given below is $5$: $CH_4, CO_2, NO, H_2O_{(l)}, H_2O_{(g)}, O_2, O_3$.
The correct answer is: