Which of the following gases causes depletion in the ozone layer?

Which of the following causes "blue baby syndrome"?

The pollution due to oxides of sulphur gets enhanced due to the presence of:
$(a)$ particulate matter
$(b)$ ozone
$(c)$ hydrocarbons
$(d)$ hydrogen peroxide
Choose the most appropriate answer from the options given below:

Match $List-I$ with $List-II$:

$List-I$ (Pollutant)	$List-II$ (Source)
$A$. Microorganisms	$I$. Strip mining
$B$. Plant nutrients	$II$. Domestic sewage
$C$. Toxic heavy metals	$III$. Chemical fertilizer
$D$. Sediment	$IV$. Chemical factory

Choose the correct answer from the options given below:

What is smog? How is classical smog different from photochemical smog?

Acrolein $(X)$ is one of the chemicals formed when $O_3$ and $NO_2$ react with unburnt hydrocarbons present in the polluted air. The structure of '$X$' is