1) Paper is one of the most frequent waste materials, but it can be recycled.
2) Nuclear waste can contaminate the groundwater.
3) Pesticides are usually poisonous substances. But organic fertilisers, e.g. manure, are harmless.
4) Coniferous forests in the Northern Bohemia were polluted by acid rains.
5) Chemical factories discharge large amounts of waste water into rivers.
6) Paper, glass, plastics, and metals are recyclable materials.
7) Acid rain is caused by discharging gases.
8) CO2 is a pollutant which probably contributes to global warming.
9) Changes in the climate are due to pollution of the atmosphere.
