Word-substitutes

That-those
A word-substitute is for the replacement of the noun given above. It is often followed by the preposition of or an attribute. It is translated by the noun, which it replaces or there is no translation at all.	The story of the telephone is similar to that of the telegraph.( История развития телефона схожа с историей развития телефона) . The first solar battery operated on semiconductor crystals similar to those used in transistors. Первая солнечная батарея работала на полупроводниковых кристаллах, подобных кристаллам, используемых в транзисторах.

These
It is the substitute of a noun, translated by the pronoun они.	Composite coatings are very important in protection of steel surfaces. These may contain more than two components. Сложные покрытия очень важны для защиты поверхности стали. Они могут содержать более двух компонентов.

One
One-ones; it is the substitute of a noun. It is translated by the noun, which it replaces or there is no translation at all. The translation of article the before a word is тот, та, то.	We shall replace the old machines by new ones. Мы заменим старые машины новыми. The method is the one which is much spoken about. Это (тот) метод, о котором много говорят.

1. Correct the sentences where necessary. Some of these sentences need a/an.

1. Chemical elements may be added to intrinsic silicon to alter its conductivity.

2. Our lives would be very difficult without electricity.

3. Press a button and the small device, resembling in many ways table-top calculator, starts lesson.

4. Typical donor impurities for silicon are arsenic, phosphorus and antimony.

5. Experts from Paris institute have used an electronic photo camera to obtain scientific proof.

6. Who doesn’t want to learn a foreign language in two or three weeks?

7. Although paper is a poor conductor, it is by no means a perfect insulator.

8. Another use for a diode is to maintain a special voltage level for a signal.

9. Robot building has become rather large sphere in our days.

2. Complete the sentences using the following. Use the where necessary.

(the) materials (the) same (2) (the) electrons

(the) semiconductors (the) task (the) tube

1. A transistor may perform … function as a vacuum-tube triode.

2. One method of generating free electrons is to expose certain … to light.

3. One integrated circuit can carry out … of several hundred transistors.

4. … are considered to be widely used in rectifiers, radio receivers, high-frequency technique, lasers, etc.

5. A grid placed near the space charge is better able to stop … than one placed farther away.

6. When a triode operates, the cathode emits … .

7. As the positive voltage of the plate becomes greater with respect to the cathode, current flow through … increases.