ВАРИАНТ 4 I. Перепишите предложения, подчеркните в каждом из них глагол сказуемое и определите его видовременную форму. Предложения переведите:  1. Today many…

ВАРИАНТ 4

I. Перепишите предложения, подчеркните в каждом из них глагол сказуемое и определите его видовременную форму. Предложения переведите:

 1. Today many polymeric materials are produced on a massive scale.

 2. Many compounds can be decomposed when they are acted upon by different forms of    energy.

 3. The mechanic asked me if the car had been damaged.

 4. Automation is being increasingly used in all branches of industry.

 5. By 1739, thirteen newspapers were being published in British America.

 6. Swimming in California Santa Monica bay has been declared unsafe because of intensive and chronic untreated sewage dumping.

II. Поставьте следующее предложение во все времена пассивного залога:

These texts are translated into many languages.

III.Выберите правильный вариант и переведите на русский язык.

1. The Mona Lisa (painted / was painted) by Leonardo da Vinci.

2. The new cinema (be built / will be built) next year.

3. New pop groups (are much spoken / is much spoken) about among teenagers.

4. The letters (be sent / will be sent) by post tomorrow.

5. The translation (was finished / were finished) two hours ago.

6.  London (visited / is visited) by hundreds of tourists every year.

7. The dogs (were taken out/ was taken out) three times yesterday.

IV. Работа с текстом:

a) переведите текст письменно на русский язык;

b) составьте глоссарий (13-15 слов или словосочетаний терминологического характера с их значениями);

с) письменно ответьте на вопросы.

SEMICONDUCTORS

         There are materials that really occupy a place between the conductors of the electric current and the non-conductors. They are called semiconductors. These materials conduct electricity less readily than conductors but much better than insulators.      

Semiconductors include almost all minerals, many chemical elements, a great variety of chemical compounds, alloys of metals, and a number of organic compounds. Like metals, they conduct electricity but they do it less effectively. In metals all electrons are free and in insulators they are fixed. In semiconductors electrons are fixed, too, but the connection is so weak that the heat motion of the atoms of a body easily pulls them away and sets them free.     

Heat is by no means the only phenomenon influencing semiconductors. They are sensitive to light, too. Just as they are influenced by falling light, semiconductors are also influenced by all radiation. Generally speaking, they are so sensitive that a heated object can be detected by its radiation.     

Such dependence of conductivity on heat and light has opened up great possibilities for various uses of semiconductors. The semiconductor devices are applied for transmission of signals, for automatic control of a variety of processes, for switching on engines, for the reproduction of sound, protection of high-voltage transmission lines, speeding up of some chemical reactions, and so on. On the one hand they may be used to transform light and heat energy directly into electric energy without any complex mechanism with moving parts, and on the other hand, they are capable of generating heat or cold from electricity.      

Russian engineers and scientists turned their attention to semiconductors many years ago. They saw in them a means of solving an old engineering problem, namely, that of direct conversion of heat into electricity without boilers or machines. Semiconductor thermocouples created in Russia convert heat directly into electricity just as a complex system consisting of a steam boiler, a steam engine and a generator does it.

Answer the questions:

1. What are semiconductors?

2. What do semiconductors include?

3. What are semiconductors influenced by?

4. What are semiconductor devices applied for?

5. Did Russian engineers turn their attention to semiconductors many years ago?

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