VIII. Read the following sentences, substitute the underlined words by the synonymous ones choosing them from the box.

toxic		progress
huge	to keep	experts
particular	is produced	production
harmful		emission
ecological	continuously growing	power stations
thick		global warming

1. Man’s economic activities began to produce an increasingly negative effect on the biosphere.

2. The growth of giant cities accompanied by industrial development on a huge scale began to introduce enormous amounts of noxious wastes into the environment.

3. The so-called acid rain results from the release of sulphur oxide and nitrogen oxide into the atmosphere.

4. The output of such synthetic compounds as polymers, resins, plastics, synthetic materials and pesticides has become enormous.

5. The main sources of poisonous emissions are plants generating electricity, industrial boilers, large smelters and automobiles.

6. The dense layer of noxious industrial gases is able to trap the heat of the sun and produce the greenhouse effect.

7. Although the new environmental problems seem very specific, their solution depends on the integrated efforts of specialists in different scientific fields.

IX. Choose the definition to some terms (in the box) which are connected with ecological problems. Follow the model when formulating definitions.

Model: Sewage is (means) the waste material and water from people’s houses and from industrial enterprises carried away in large pipes under the ground.

deforestation	pollution	ozone layer	smog
pesticide	recycling	rubbish dump	garbage

a) the process of making the air, water, or soil dirty or dangerous by adding harmful substances;

b) cutting down and burning large areas of trees (forests) destroying wildlife habitats;

c) a chemical substance used to kill harmful animals and insects by spraying the crops;

d) a layer of ozone gas high above the Earth’s surface which protects the planet from harmful rays such as ultra-violet;

e) an unhealthy mixture of fog and smoke which is found in the air in some industrial cities;

f) a place for keeping waste material thrown away;

g) things that have been thrown away because they are no longer needed;

h) special treatment of something which has already been used so that it may be used again.

X. Look through the texts in this unit, find Participles (I&II), Infinitives and Gerunds. Try to define their functions in the sentences.

XI. Answer the questions on the text.

1. What were the first ecological changes?

2. What was ecological situation in the twentieth century connected with?

3. What were the main factors influenced the modern ecology?

4. How are the acid rains formed?

5. How does the greenhouse effect take place?

6. What does the destruction of nature and natural balance lead to?

7. What are the possible ways of solving ecological problems?