Put the verbs in brackets into appropriate forms, active or passive.

1. The discovery of electron … to a revolution in electrical science.(lead)

2. Electronics … to appearance of television, sound pictures and long-distance calls. (contribute)

3. Until 1955 vacuum tubes … the principle building blocks of electronic circuits (be).

4. Vacuum tubes … still widely … in oscilloscopes. (use)

5. Crystal valves … long before the invention of vacuum tubes. (know)

6. In 1948 American scientists … the first transistor. (invent)

7. Solid-state devices … the growth of electronics. (accelerate)

8. Transistors … from parts which do not wear out. (make)

9. Transistors … very little power. (waste)

10. The students … a problem they had to solve. (give)

11. The laboratories our students work in … with the best equipment. (provide)

12. The substance … in detail by the engineer in two months’ time. (study)

13. The facts you … about illustrate the use of generators.(tell)

Change the following sentences into passive structures.

1. Manufacturers produce transistors using a highly automated process.

2. Mechatronic circuits have replaced electromechanical devices in controlling appliances and machinery.

3. A transistor can control its output.

4. Vast numbers of products include amplifiers for sound reproduction, radio transmission and signal processing.

5. We have recently undertaken a new program.

6. They had put forward a new idea by the end of the meeting.

7. They will have made an analysis of the data by next Monday.

8. They had done an interesting research before they got the better results.

9. Lately we have published a few papers on this problem.

10. Recently they have given some useful recommendations.

11. We have just given a few illustrative examples.

12. They will have introduced some new measuring instruments by the beginning of the presentation of the new method.

Translate the following sentences paying attention to the verbs in passive voice.

1. The transistor can be used to turn current on and off in a circuit.

2. The amount of current is determined by other circuit elements.

3. Transistors are commonly used as electronic switches.

4. This property is called the gain.

5. Electron tubes have been developed that can be operated at tens of thousand of volts.

6. High frequency operation is better achieved in electronic tubes.

7. This invention was much written about at that time.

8. A lecture was attended by a great number of students.

9. The rotation of the planets around the Sun is affected by the gravitation.

10. The lecture will be followed by a discussion.

11. Final examinations are taken at the end of the course.

12. A new production plan will be discussed at the meeting.