Air pollution is caused due to :

1. cutting of green plants
2. smoke given out by factories
3. gases like carbon monoxide, sulphur dioxide, etc.
4. all of the above.

The gases which cause acid rain are:

1. sulphur dioxide and oxygen
2. nitrogen and oxygen
3. carbon dioxide and water vapour
4. nitrogen dioxide and sulphur dioxide.

Common air pollutants that cause respiratory diseases are:

1. ozone
2. inert gases
3. dust and smoke
4. water vapour

The gas responsible for ozone depletion is:

1. oxygen
2. chlorofluorocarbons
3. carbon dioxide
4. sulphur dioxide