ВАРИАНТ 4 I. Перепишите следующие предложения, подчеркните в каждом из них глагол-сказуемое и определите его видо-временную форму и залог. Переведите предложения на…

ВАРИАНТ 4

I. Перепишите следующие предложения, подчеркните в каждом из них глагол-сказуемое и определите его видо-временную форму и залог. Переведите предложения на русский язык.

1. Much work had been done for improving soil fertility on this farm.

2. Modern agriculture is developing in close contact with science and new technologies.

3. Our industry will increase the output of faster and more powerful tractors.

4. The driver usually increases speed gradually.

5. Some cities are so noisy and polluted that in many places vehicles have been banned in the city centre.

6. I was watching TV from 7 to 9 p. m. yesterday.

7. Ann had done her homework before her parents came.

II. В следующих предложениях подчеркните Participle I и Participle II установите функции каждого из них, т.е. укажите, является ли оно определением, обстоятельством или частью глагола-сказуемого. Переведите предложения на русский язык.

1. A letter sent from St. Petersburg today will be in Moscow tomorrow.

2. When sending the telegram, she forgot to write her name.

3. A fish taken out of the water cannot live.

4. They will be working at that time tomorrow.

5. He had translated the text before I came.

III. 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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