(a) What are the two main pollutants that contribute to acid rain?

(b) Where do these pollutants come from?

(c) What direct or indirect effect is 'acid rain' thought to have on (i) lakes, (ii) forests and  (iii) buildings?

(a) The main pollutants in acid rain are sulphur dioxide and oxides of nitrogen. Ozone may also be a pollutant.

 (b) Sulphur dioxide and oxides of nitrogen come mainly from burning coal in power stations.   Oxides of nitrogen come from burning petrol and diesel in cars and lorries. Ozone results from reactions of these gases in the atmosphere.

 (c) Acid rain (i) leads to acidification of lakes which kills all the living organisms; (ii) directly or indirectly leads to the premature death of trees and the destruction of    forests; (iii) the erosion of buildings and other structures having limestone, marble, mortar etc.