Select the appropriate option regarding the natural aging of a lake.

The cooking gas cylinder is filled with .......

Match the following important dates/events related to environmental legislation in India:
$(i)$ Air (Prevention and Control of Pollution) Act
$(ii)$ Environment (Protection) Act
$(iii)$ Water (Prevention and Control of Pollution) Act $(1974)$

In Arcata,the integrated wastewater treatment was developed by creating a series of $6$ connected marshes. Its function is $............$

Match the following columns:

Column-$I$	Column-$II$
$(a)$ Electrostatic Precipitator	$(1)$ Platinum,Palladium,Rhodium
$(b)$ Scrubber	$(2)$ Collecting plates
$(c)$ Catalytic Converters	$(3)$ Recycled modified plastic
$(d)$ Polyblend	$(4)$ Water or lime spray

$A$: High concentration of atmospheric $SO_2$ and $NO_x$ causes acid rain.
$R$: It causes damage to foliage and growing points of plants.