Пояснения к тексту:

1. semiconductor – полупроводник;

2. sensitive – чувствительный;

3. on the one hand – с одной стороны.

Semiconductors

1. The periodic law of lements discovered by Mendeleyev had a number of important scientific and industrial results, one of them being the discovery of germanium. Germanium is the semiconductor used in most transistors available at present.

2. But what are semiconductors? They 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.

3. It is not difficult to understand that the term " semiconductor " has been used because the material in question really occupies a place between the conductors of electric current and the non - conductors, that is insulators. The term shows that they conduct electricity less readily than conductors but much better than insulators.

4. Minerals and crystals appear to possess some unexpected properties. For instance, it is well known that their conductivity increases with heating and falls with cooling. As a semiconductor is heated, free electrons in it increase in number, hence, its conductivity increases as well. However, heat is by no means the only phenomenon influencing semiconductors. They are sensitive to light, too. Take germanium as an example. Its electrical properties may greatly change when it is exposed to light. With the help of a ray of light directed at a semiconductor, we can start or stop various machines, effect remote control, and perform lots of other useful things. 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.

5. As previously mentioned, 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.

Упражнение 5. Прочитайте пятый абзац и выполните задание:

Write down as many applications of semiconductors as you can.

Вариант 3

Упражнение 1. Перепишите и письменно переведите на русский язык следующие предложения. Помните, что объектный и субъектный инфинитивные обороты соответствуют придаточным предложениям. Пользуйтесь таблицами 21-24[17]⁶ и образцом выполнения [16].

1. The properties of the new material are known to be determined next month.

2. All the changes of temperature and changes of state are said to be discussed.

3. They wanted the device to be put into operation as soon as possible.

Упражнение 2. Перепишите и письменно переведите на русский язык следующие предложения. Обратите внимание на перевод зависимого и независимого (самостоятельного) причастных оборотов. Пользуйтесь таблицами 25-29 и образцом выполнения [16].

1. The computer's electronic memory recording all the operator's commands, the picture of deviations was produced.

2. Having done a given number of operations, the machine stopped automatically.

3. It is being late, we decided to stop working.

Упражнение 3. Перепишите и переведите на русский язык следующие условные предложения. Пользуйтесь таблицами 11-13[17] и образцом выполнения [16].

1. If the service life of the instrument had been prolonged, the economic effect would have been better.

2. It would be impossible to ensure the full supply of energy without atomic power stations.

3. If the scientists use the new methods, they will have better results.

Упражнение 4. Прочтите текст и выполните следующие задания:

1. Укажите абзац, который сообщает об обширном применении компьютеров.

2. Укажите абзац, более всего соответствующий ответу на вопрос текста.

3. Перепишите и письменно переведите первый, второй, третий и четвертый абзац текста.