39. Прочтите следующий текст. Найдите в каждом предложении группу «подлежащее-сказуемое». Переведите предложения с глаголом-ска­ зуемым в страдательном залоге:

The book Planet Earth, an Encyclopedia of Geology is often referred to because it gives much information on the geological his­tory of the Earth, the rocks of Earth, the processes which occur in the Earth, etc. For example, sedimentary rocks form a small proportion by volume of the rocks of the Earth's crust. They are formed from sediments, accumulations of solid material. The oldest sedimentary rocks were known some 3,500 million years ago. The processes which lead to the formation of sedimentary rocks are going on around us and different sediments are being deposited and may later be changed into rocks. Most sedimentary rocks have been classified according to their grains size. Great attention is also paid to the rocks of the oceans because they are less studied.

40. Укажите, в каких предложениях модальный глагол употребляется с инфинитивом в страдательном залоге. Переведите предложения:

1. We can observe physical weathering in deserts and high mountains. This phenomenon can best be observed in places where the changes in temperature are great.

2. Sedimentary rocks can be more or less unconsolidated during the process of sedimentation.

3. Sedimentary rocks can be found at or near the surface of the Earth.

4. Igneous activity can be considered as one of the most funda­ mental Earth processes.

5. As is known, igneous rocks can be extrusive and intrusive.

6. Like sands, sandstones can be divided into fine-grained, me­ dium-grained and coarse-grained.

7. One can divide all sediments into consolidated and unconsoli­ dated rocks.

41. Соедините главные предложения с придаточными.

1. Rock disintegration does a) whereas with the fall of not occur uniformly and night they begin to con- at an equal rate tract.

2. Under the influence of 6) until they are finally trans- contraction and expans- formed into sand, gravel or ion rock cracks are dust.

formed в) because it does not cause

108 Unit 4

3. During the day under any change in the chemical the influence of heat, composition of rocks, rocks expand r) which gradually become

4. Physical weathering can wider and deeper.

best be observed in the д) as rocks are composed of deserts different minerals.

5. Rocks gradually decom- e) where the changes in tern- pose perature are great.

6. The process of physical weathering is purely mechanical

42. Задайте вопросы по образцу (Специальный вопрос).

Образец: Weathering takes place in the upper layers of the Earth's crust, (where?) -> Where does weathering take place?

1. The main cause of physical weathering is the change in tem­ perature, (what?)

2. Physical weathering can best be observed in the deserts and high mountains, (where?)

3. Oxygen, carbon dioxide and water are the main chemical agents which cause the destruction of rocks, (what agents?)

4. Certain marine organisms accelerate the destruction of rocks by making holes in them to live in. (how?)