И. А. Курбасова Е. И. Силантьева

Урок 14
Грамматика: Сослагательное наклонение в условных предложениях (§ 22, 59).
ВВОДНЫЕ УПРАЖНЕНИЯ К ТЕКСТУ А
1. Переведите предложения со сказуемыми в сослага­тельном наклонении. Скажите, какие предложения выра­жают неосуществимые действия (укажите формальный показатель, по которому можно определить предложения этого типа).

1. It would take about 3 hours to get from Moscow to Leningrad if the train speed were 300 kph. 2. Switching operations would have been performed with greater difficul­ties if the diesel locomotive had not been designed. 3. If the refrigerator cars had not been devised, the conveyance of goods for long distances would not have been possible.

4. If the railways were built in open, level country, the track construction work would be less expensive and difficult.

5. If the ballast were poorly maintained, the track struc­ture would get destroyed. 6. The locomotive could better meet traffic requirements, if it had a larger tractive power. 7. If we knew more efficient methods of electricity transmis­sion, the energy losses would not be so large.

2. Прочтите развернутый план текста А, не поль­зуясь словарем; определите значения выделенных слов и сло­восочетаний, исходя из контекста; перескажите содержа­ние каждого пункта плана по-русски.

(1) It is not so hard to build railways in open, level country. But railways must be built in cities, they must cross high mountains and wide, deep rivers.

(2) Mountains and rivers are obstacles which people met in the past and meet today in the way of their travel. To overcome these obstacles people have to build such engineering structures as tunnels and bridges.

(3) People began to build bridges in the pre-historic times. Different natural phenomena (явление) might suggest the idea of a bridge: a tree fallen across a river, lianas in tropical countries, and other similar things.

(4) Today, we have many types of bridges: simple beam bridges (балочный мост), beautiful arch bridges (арочный мост), very complicated suspension bridges (висячий мост) and other structures. Some of them are built of steel, others are built of concrete.

(5) At first people designed bridges empirically, that is, they depended on the experience (опыт) gained from their successes and failures. They had no basic knowledge of mathematics and did not know how the wind influences the bridge structure, which resulted in great tragedies.

(6) Then people learnt how to make exact calculations of the bridge strength taking into consideration the prin­ciples of aerodynamics (that is, the force of the wind) and the achievements of other engineering sciences and applied mathematics.

(7) The development of railways was closely connected with bridge building because railways necessitated the erec­tion of stronger bridges capable of carrying much greater loads than ordinary road bridges.

3. Прочтите текст со словарем и дайте ответы на следующие вопросы.
1. What made people build bridges? 2. What natural phenomena might suggest primitive people the idea of building bridges? 3. What did people have to do in order to increase the strength of natural bridges? 4. What types of bridges are described in the text and what are the differ­ences in their structure? 5. What was J. Roebling and what contribution did he make to bridge building? 6. What is meant by the "empirical method" of bridge building? 7. Why did some of the early bridges collapse? 8. What caused the collapse of the Tay Bridge and how did the accident happen? 9. What sciences influence the art of bridge building? 10. Is the construction of bridges and the development of railways closely connected? Prove it by the facts from the text.