Exercise 10. Change the following sentences active to passive, passive to active

Through the years, automobiles have been made more and more powerful. 2. New cars produce much more polluting exhaust than older ones did. 3. Some solid wastes can be destroyed by burning them. 4. Most treatment plants prevent dangerous organic wastes from upsetting the natural cycles in water. 5. Mechanisms called catalytic converters now remove some of the polluting materials, produced by automobile.

Exercise 11. Put all types of questions to the following sentences.

The automobile engine is an example of a very useful technological development that harms the environment. 2. Through the years, automobiles have been made more and more powerful. 3. Plastics also indirectly cause pollution when they are produced.

Exercise 12. Find all verbs in the text and put them into correct columns. Present Simple Past Simple Present Perfect       Infinitive (with or without to) Passive Voice Modal verbs

Exercise 13. Here are the answers to some questions. Write the questions.

The automobile engine. 2. We must do something to eliminate pollution from automobiles. 3. Economic and social causes. 4. Technological advances. 5. Dangerous organic wastes.

Exercise 14. Give definitions to the following terms. Invention, exhaust, sewage treatment plant, organic wastes, environmental pollution.