What are the major pollutants in large cities?

Which of the following components,when increased in concentration in the atmosphere,causes acid rain?

State the sources of dissolved oxygen in water.

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

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:

Give the examples of particulate pollutants.