The first laser having been built about 30 years ago, scientists developed

Several types of lasers.

Having developed quantum generators called lasers, scientists are looking for

Practical use for a new kind of ray which is millions of times brighter than the

Sun.

Semiconductor lasers are able to transform electric energy directly into light

Wave energy, this property of semiconductor lasers opening up new

Possibilities of producing extremely economical sources of light.

III. Перепишите и письменно переведите предложения, содержащие придаточные предложения условия.

If the Earth had no atmosphere, its heated surface would quickly radiate back

Into space all the energy which reaches it from the Sun.

Had the checking up of the experimental data not taken so much time, we

Should have completed our work long ago.

IV. Перепишите и письменно переведите текст на русский язык.

LASER

The laser has become a multipurpose tool. It has caused a real revolution in technology and in the nature of productive labour.

The laser can cure diseases. It has become indispensable as a means of space communication. Its beam produces a sharp picture on the TV screen. Moreover, it can increase the size of the TV screen to that of a modern cinema. The laser cuts steel, pierces hard alloys and diamonds and drills holes through them a few microns in diameter.

Nevertheless, the laser no doubt has innumerable other applications which we are still to discover.

Let us begin with optical methods of data processing. Technological progress calls for (требовать) ever more efficient electronic computers. Multipurpose computers capable of performing more than ten million operations per second have already been designed and built. Laser devices will apparently make it possible to build extremely fast computer elements capable of doing up to a thousand million operations a second.

Today the enterprises are producing a number of machine tools and automatic devices intended for production lines. The machine tools for working jewel bearings for the watch industry and diamond files for wire drawing are now used on a wide scale. These machine tools bring a substantial economic effect. Machine tools employing carbon dioxide lasers for cutting quartz and glass pipes and for crystal and glass engraving are being introduced into industry. Lasers have found an application in the printing industry.

КОНТРОЛЬНОЕ ЗАДАНИЕ №4.

ВАРИАНТ 4.

I. Перепишите и письменно переведите на русский язык предложения, принимая во внимание, что объектный и субъектный инфинитивные обороты большей частью соответствуют придаточным предложениям.

The application of plastics enables the railway to receive light and strong cars

With good resistance to mechanical damage.

We heard the operation experts demand the reduction of the overall weight of

Vehicles (транспортные средства).

This type of engine is said to have some advantages.

Plastics used in transport are supposed to have no special reinforcement.

II. Перепишите и письменно переведите на русский язык предложения, учитывая различия в переводе зависимого и независимого причастных оборотов.

Zinc being the cheapest metal with a strong tendency to lose electrons, we

Commonly use it for the production of electric current.

Electrical machines perform a giant’s share of the work done today, this share

Steadily increasing.

Having obtained new devices the researchers could make complex

Experiments.

III. Перепишите и письменно переведите предложения, содержащие придаточные предложения условия.

If somebody wants to design a car of the advanced type, he must take into

Account the properties of some of the new materials.

Had there been better conditions, the construction of the new car body would