Causes of pollution
Devi :              What is one cause of air pollution?
Nick :              Automobiles are a major cause
                        of air pollution.
Geoff :            Do factories also cause pollution?
Nick:              Yes, they do. Factories, such as this
                       one , cause lots of pollution.
Geoff :           Really ?
Nick :             Yes. They pollute the air and release
                        wastewater into the sea.
  Video CD  Dynamic English 2