The water problem

Answer the questions

EXERCISES

VOCABULARY

аdverse - несприятливий huge - величезний berry – ягода hunt - полювати clean up - очищувати niche - ниша community - співтовариство noxious - шкідливий degrade - розкладати offender - порушник disturb - турбувати

pollution - забруднення environment – навколишнє середовище root - корінь fit in –підходити trap - пастка food - їжа upset - порушувати habitat - місце проживання waste - відходи herd – стадо, отара

1. What is called an ecosystem?

2. What maintains an overall balance in the system?

3. What alters the environment?

4. When was the balance of nature first disturbed?

5. What influences greatly the environment in recent years?

2. Translate the following sentences:

1. For many centuries the problem of air pollution was not paid attention to. 2. We ought to protect the environment for it is in danger of human activity. 3. Industrial enterprises must use filters for exhaust gases to be purified. 4. They investigated carbon monoxide and sulphur oxide for the reason of their toxic properties. 5. The experiment lasted for three hours. 6. The ecosystem has a definite role to play for an overall balance has to be maintained. 7. Plants and animals fail to live without oxygen. 8. Many countries on the globe fail to fight man-made pollution. 9. The experiment was very tedious but they failed to get the desirable results. Transportation devices all over the world fail to prevent air from exhaust gases pollution. 10. Their attempt to make this experiment failed.

3. Translate the sentences:

1. The problem concerned is known to be the most difficult one. 2. Having investigated the properties of this polymer they come to a definite conclusion. 3. The experiment being very important, we paid special attention to the product obtained. 4. The problem of environmental protection is very important, a special committee having been set up under the UNO. 5. The development of modern industry is likely to be accompanied by the development of wasteless production. 6. Concentration of CO happens to be rather high in air. 7. Primitive man appeared to disturb the balance of nature by farming and cattle breeding. 8. Ultraviolet radiation from the Sun seems to make the evaporation of some substances from trees and Earth's crust to react with atmospheric oxygen.

Water is the most common of all liquids and probably the most useful. Naturally occurring forms such as sea water, rain water and lake water are never pure. Consumption increases annually, millions of tons are used each day in industry, so in this respect there is no wonder that there is a water problem. The answer to heavy demands might well be the sea which covers most of the Earth's surface.

Sea water varies in composition, but is, in fact, a vast store house of substances apart from water. In the English Channel there is about 3.5 per cent of solids dissolved in the water, in the Red Sea about 4.1 per cent, while in the Baltic it can be as low as 0.5 per cent. Sodium chloride, common salt, is the most abundant of the solids present. From your knowledge of separation so far, you can easily understand that distillation of sea water would give pure water and leave the solids in the distillation vessel. Of course this has been realized for a lone, time but the difficulty has been in carrying out this operation economically. To satisfy the heavy demands of industry, a great deal of fuel would be needed to carry out the distillation. However, using the Sun as the source of heat, purification of sea water has successfully been carried out in some countries in recent years.

Дата добавления: 2015-01-03