Добавил:
Upload Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:

31-03-2014_15-32-32 / Резина 4

.doc
Скачиваний:
7
Добавлен:
11.05.2015
Размер:
15.67 Кб
Скачать

Контрольная работа по английскому языку № 4

для студентов I курса очно-заочного факультета ЛГТУ

всех технических специальностей

Вариант 4

RUBBER

When Columbus landed in the New World, he found the natives playing with heavy black balls made of some sort of vegetable gum. Later explorers found that the Aztecs used similar balls in a game that was something between basketball and tennis. Then, in the eighteenth century a Frenchman took a great interest in its production and application and stimulated others to study the material. An English chemist discovered its first practical use - the rubbing out of pencil marks - from which its English name "rubber" was derived. The main difficulty hindering further applications was the problem of producing a uniform, stable product from the milky liquid obtained from the rubber tree.

This difficulty was overcome only when the study of the white liquid was taken up in the later part of the nineteenth century. In 1873, seeds of rubber-producing plants had been sent from the Amazon region to the Kew botanical gardens in England. Then, they were sent to Ceylon and Singapore and formed the beginnings of the new rubber plantations in India, Malaya and the East Indies.

In the meantime, scientists had tried to adapt this elastic material to technical uses. In 1834, there was discovered a primitive type of vulcanization - a process of transforming the soft natural rubber into a harder, more durable solid. Vulcanization was greatly improved when a fortunate accident led to the perfection of this method: during an experiment a mixture of soft rubber and sulphur was dropped on a hot stove.

Rubber vulcanized in this way, however, is hardly suitable for making tires for automobiles, bicycles, and airplanes - applications that became increasingly important shortly after the turn of the century. The problem was solved by mixing crude rubber with mineral powders, oils and fibres to suit individual requirements.

Before long, however, the automobile tire industry was looking for greater supplies of rubber to meet the fast-rising demand especially during both World Wars. The technologists then began an extended research into the chemistry of synthetic rubber. This resulted in a number of products, which help considerably to overcome the shortage of natural rubber and prove their usefulness in a variety of applications.

A large contribution in this field was made by the outstanding Russian chemist A. M. Butlerov. He obtained isobutylene - an organic compound, which later on was used for the production of synthetic rubber. The first specimens were very inferior in their resistance to wear, but latest rubber-like substances have actual advantages over the tree-grown liquid. In fact, the synthetic product is not rubber at all. It is an assembly of molecules derived from such products as coal, petroleum and limestone. Synthetic rubbers are better for many purposes than the natural product. Chemists know at least 3,000 formulas for making rubber-like substances.

A further step in rubber technology was the combining of rubber with metals, wood and asbestos so as to obtain a product having the elasticity of rubber and the strength or special properties of the other components. This phase of research greatly increased the potential uses of rubber. You may imagine highways of tomorrow surfaced with a rubber coating resistant to frost and moisture, flexible enough to expand or contract without cracking. Chemical compounds make it skidproof in all weather, cutting down accidents.

Road building is but one of many fields of engineering that open up new uses for synthetic rubber.

I.Прочитайте текст и переведите его на русский язык письменно.

II. Заполните пропуски в предложениях, используя текст, и переведите пропущенные слова на русский язык.

1) When Columbus . . . in the New World, he found . . . playing with heavy black balls made of some sort of . . . . 2) In the eighteenth century a Frenchman . . . . . . in its production and application and simulated others to . . . . 3) In 1834 there was discovered . . . . . . – a process of transforming the soft natural rubber into a . . . . 4) Before long, however, the automobile . . . was looking for . . . to meet . . . especially during both World Wars. 5) A large . . . was made by . . . A. M. Butlerov. 6) He obtained isobutylene - . . . which later on was used . . . . 7) A . . . . . . in rubber technology was . . . so as to obtain a product . . . . . . .

III. Найдите в тексте и выпишите предложения с глаголом в страдательном залоге. Укажите временную форму глагола. Переведите предложения письменно.

Образец: She was asked to bring the book.

was asked – Past Simple Passive.

Её попросили принести книгу.

IV.Раскрывая скобки, напишете каждое предложение три раза, построив условные предложения I, II и III типов.

Образец: If you (to be) free, I (to come) to see you.

If you are free, I will come to see you.

If you were free, I would come to see you.

If you had been free, I would have come to see you.

1) If I (to translate) the article, I (to find out) all about this discovery. 2) If she (to ask) me, I (to tell) her all about it. 3) If you (to ring) me up, I (to tell) you a secret. 4) If you (to be) a poet, you (to write) beautiful poetry. 4) If I (to lose) my money, I (to be) very sorry.

V.Раскройте скобки, употребляя глаголы в требуемой форме.

1) How slippery it is! If it (not to rain), it (not to be) so slippery. 2) I am so glad I was able to attend the lecture yesterday. You (to be) displeased if I (not to come)? 3) You would not feel so bad if you (not to smoke) too much. 4) If you gave me your dictionary for a couple of day, I (to translate) this text. 5) If Mary (not to get) up at half past eight, she would have been late for school.

VI.Переведите следующие предложения на английский язык.

1) Если бы он не был талантливым художником, его картину не приняли бы на выставку. 2) Если бы я знал немецкий, я бы читал в оригинале. 3) Если бы вы хотели узнать этот трудный материал, вы бы были активнее. 4) Если бы она была сильна в иностранных языках, она попыталась бы поступить на факультет иностранных языков. 5) Если бы у меня болел зуб вчера, я сходил бы к врачу.

Соседние файлы в папке 31-03-2014_15-32-32