II. Arrange synonyms in pairs and translate them:

a) investigation, rapidly, valve, shape, immense, to expand, speed, to examine, to receive, to apply, significance, efficient;

b) importance, research, to use, effective, to get, to study, velocity, to extend, form, tube, fast, tremendous.

Ш. Arrange antonyms in the pairs and translate them:

a) to cover, directly, old, much, more, rapidly, small, visible, powerful, long, before, to take, significant, effective;

b) to uncover, ineffective, to give, after, powerless, short, large, invisible, slowly, less, little, new, indirectly, insignificant.

IV. Put the words in order:

1. Is, tungsten, of, a, conductor, electricity. 2. To push, through, the, the, filament, electrons. 3.

Electrons, to get, easily, are, able, very, many, through, the filament. 4. Tungsten, of, the, atoms, the,

constantly, electrons, are, pushing. 5. Electric, the, are, lamp, first, the lamp, carbon, was.

V. Complete the following sentences, using active vocabulary:

1. Tungsten is conductor of electricity that is its atoms allow…… 2. The filament is hardly thicker than a human hair, however, and not vary…..3. The filament is hardly thicker than a human hair, however, and not vary ……4. The first electric arc lamp for practical application was ……5. In spite of that many electrons are trying to push through because ……6. The English scientist Davy began demonstrating it first in London in 1810 but these were no machines …… 7. Only after creating a vacuum in the bulb the problem of practical use ……

VI. Which of the following statements are true or false? If statement is wrong, correct it:

1. A filament is made of the silver tungsten. 2. Tungsten is a transistor of electricity. 3. The atoms are

constantly pushing the electrons of tungsten. 4. The tungsten filament becomes cold and bright to glow. 5. Carbon is a good material for filaments. 6. The filament is not connected to a generator.

VII. Answer the following questions:

1. What will you be able to see if you look at the electric light bulb? 2. What material is a filament made of? 3. Is tungsten an insulator? 4. Can tungsten conduct electricity? 5. Why are there tree electrons in the tungsten wire? 6. What are the electrons doing when the filament is connected to a generator? 7. What is heat? 8. Why is the filament enclosed in the glass bulb? 9. What scientists worked at the problem of carbon arc lamps? 10. Why was the invention of the metal filament important?

VIII. Describe an electric lamp and the process of producing the light in it.

IX. Define the tense-forms of the verbs in the following sentences and translate them into

Ukrainian.

1. Tomorrow at that time we will be working at the laboratory. 2. The scientists are using the energy of atom in various spheres of life. 3. The engineers where attaching the wires to the devices when I come in. 4. At present they are studying various aspects of this problem. 5. When we listen to the radio program we are using the rays that are called radio waves. 6. The scientist was solving a new problem when we visited his laboratory last week. 7. The student was carrying out this experiment for twenty, minutes. 8. Molecules in a gas are constantly moving. 9. The solar battery is converting the energy of sun rays directly into electric energy. 10. Our scientists are developing new types of electronic and cybernetic devices. 11. We were looking for a more simple method of solution but could not find it. 12. The engineers were discussing the advantages of this new system for two hours. 13. The device will not be working for such a long time. 14. The apparatus will be working when you come.