Analyse the Adverbial Clauses of Condition. Open the brackets use the correct verb forms.

1. If she rings me up, I (to ask) her to come to see us. 2. If he were here now, he (to tell) us many interesting things about his trip. 3. If they (to join) us, they would have had a very good time. 4. Had we known all these facts before, we (to write) you about them long ago. 5. If I (to have) time yesterday, I should have gone to the concert with you. 6. If I (to go) to Odessa, I shall stay at my friends’. 7. Do you think she (to agree) to join us if we asked her about it? 8. If she (can), she would certainly helped you. 9. If she (to be warned) in time, she would not have missed the train.

7. Define the types of conditional clauses in the following complex sentences. Translate them into Ukrainian:

1. If a solid body or a liquid is heated, it will usually expand. 2. The measurements were always correct provided the necessary instruments were used. 3. It would be better if some experiments were repeated. 4. If the earth were as hot as Venus, the oceans would evaporate. 5. If he had prepared the material beforehand, he might have done the work quite easily. 6. If they had completed the research, the results would have been discussed at the conference. 7. If ozone were suddenly withdrawn from the atmosphere, we should be killed within a few minutes by the sun’s ultra-violet light.8. If land surrounding a lake receives too much fertilizer, unabsorbed fertilizer washes out of the soil into the lake water. 9. Provided a liquid had evaporated into a closed space, its gaseous molecules would have left the liquid surface. 10. If water is taken from the lake for use, water filters become clogged with weeds. 11. If there were no dust, the air would become supersaturated with water. 5. If air is cooled sufficiently, it can be converted into liquid. 12. Had water been added to the mixture, more acid would have been formed. 13. If a chemist is to determine very small samples of matter, he should use a microscope. 14. If we did not know the nature of radioactive elements, it would be difficult to deal with them. 15. If he was at the library yesterday, why didn’t he return the books? 16. The study of any substance would be incomplete unless we investigated the properties of that substance and the methods of obtaining its components.

8. Translate in written form the following texts into Ukrainian, mind the Conditional sentences:

Text 1

Dust in the air consists of solid particles of a number of substances so small that they do not readily settle. The presence of dust in the air is important in that dust particles serve as nuclei for the condensation of water vapour.

If there were no dust, the air would become supersaturated with water and clouds and rain would be formed. Moisture would condense directly on the surface of solid objects.

Dust also includes living organisms, some of them lead to disease and infection.

Text 2

Air contains nearly constant proportions of three elementary substances, namely nitrogen – 75.4 per cent, oxygen – 23.2 per cent and argon – 1.2 per cent by weight.

The relative proportions of water vapour in the air is usually stated in terms of relative humidity. The relative humidity affects hard the rate of evaporation.

If the relative humidity were low, evaporation would occur rapidly. If the relative humidity were high, evaporation of water would occur slowly as the air is nearly saturated.

Text 3

The most important source of oxygen is the air. Air may be changed into a liquid both in the laboratory and at the plant.

If liquid air were boiled, nitrogen would escape from the solution readily and more rapidly than oxygen. By the use of many devices, most of the nitrogen may be boiled out.

Nitrogen itself is known to be inactive. If the atmosphere contained much more than the normal amount of it, the chemical activity of the oxygen, an active ingredient of air would be too much retarded.

Text

1. Look through the following text and find the answers to the given questions:

1. Who eats plants?

2. What is the form of carbon in the Earth’s crust?

3. What energy is used by green plants and algae and what do they do with it?

4. What are the ways of forming carbon dioxide?

5. How are human activities estimated now?

6. Why is hard now to estimate them?

It is known, that carbon, like water, cycles from the Earth into the atmosphere and back again. Green plants and algae use the sun’s energy to convert carbon dioxide (and water) into carbohydrates. The plants are eaten by animals, including people and fish, who exhale carbon dioxide. It was discovered that carbon dioxide is also formed by decomposition of dead animals and animal wastes by microorganisms. The carbon dioxide passes into the atmosphere and is again used for photo synthesis. An equilibrium also exists between carbon dioxide in the atmosphere and dissolved carbon dioxide and H2CO3 in oceans and lakes. In addition it was estimated that much carbon is stored in the Earth’s crust in the form of fossil fuels – coal, petroleum, and natural gas – and in the form of limestone and coral. Since the middle of the nineteenth century, it has been observed that the production of carbon dioxide by the combustion and the decomposition of limestones is increasing rapidly. In addition, it has been proved that destruction of tropical forests is reducing the quantity of carbon dioxide used up by photosynthesis. Human activities have now reached a scale where interference with the natural carbon cycle may well be significant. The longest continuous records of the concentrations of carbon dioxide in the atmosphere unfortunately were made only in 1958, and therefore it’s hard to be sure how harmful human activities have been since that time.

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