The consequence of global warming may be the following:

Which of the following statements about smog is/are correct?
$(i)$ Smog formed on sunny days contains oxidizing molecules.
$(ii)$ Photochemical smog contains many reactive molecules.
$(iii)$ The main polluting components of smog are oxides of carbon.
$(iv)$ The presence of carbon monoxide in air leads to the formation of ozone in smog.

Which of the following metal pollutants is present in the exhaust fumes of vehicles?

Ozone is a gas heavier than air. Why does it not settle around the Earth's surface?

$BOD$ stands for

If water pollution continues at its present rate,it will eventually