Exercise 15. The following sentences are grammatically incorrect. Make them correct

People has always polluted their surroundings. But pollution were not a major problem. Most people lives in uncrowded rural areas, and the pollutants, they produces was widely scattered. People has no pollution- causing machines or motor vehicles. The development of crowded industrial cities in the 1700's and 1800's make pollution as major problem.

Exercise 16. Put the words from the box into each gap.

Organic wastes; the sewage treatment plant; lead; the environment; technological advances__

In agriculture, industry, and transportation have greatly improved our way of life. 2. The sewage treatment plant is an example of a technological development that was designed to protect..., but which can cause pollution nevertheless. 3. Scientists and engineers are working to develop... that will also remove inorganic nutrients from sewage. 4. The treatment plants use bacteria and oxygen to break down the... and turn them into inorganic nutrients. 5. The gradual elimination of the... from gasoline has helped make automobiles less polluting.

Exercise 17. Divide the text into 5 parts and put a question to every

Part.

Exercise 18. Find out information about:

* die technological development in transportation that harms the environment;

* the mechanisms which help make automobiles less polluting;

* the development for protecting the environment, but which can cause pol­lution nevertheless;

* a troublesome solid waste;

* a major source of air pollution;