3. Fill in the gaps with articles a/an, the where necessary.

1. … special liquid was introduced into certain points of … body and … photo camera recoded … gamma rays released by … liquid.

2. … centre with up-to-date … automation ensures … safe shipping in northwestern sector of … Black Sea.

3. … new device known as LENAR has been patented in … United States, … France, … Japan, … Federal Republic of Germany and … Canada.

4. … phenomenon is of … great scientific and practical significance, offering … deeper insight into … processes which take place in … crystals under … influence of … electric field.

5. … most important fact to remember about … diode is how much … current it will pass with … given amount of … plate voltage.

4. Translate the sentences from Russian into English. Mind the usage of articles.

1. Чем дальше сетка находится от катода, тем больше анодный ток.

2. Чем шире расстояние между проволочками сетки, тем больше анодный ток.

3. Чем выше температура, тем ниже проводимость металлического проводника.

4. Чем ниже температура, тем лучше проводимость металлического проводника.

5. Use set expressions given in the grammatical table above to complete the following sentences.

1. You must be ready to go on business … .

2. You … to make such dangerous experiments.

3. … our work appeared a new device.

4. Our invention will be patented … .

5. It is … that the secret information got … of Professor Jordan.

6. This is P-N junction. There are more electrons … and more holes … .

6. Find sentences where that (those) are in the function of word-substitutes.

1. Computers are devices that are capable of very rapid and accu­rate calculations.

2. The experimental technique was similar to that de­scribed previously.

3. You know that light waves pass through glass more easily than heat waves.

4. You know that light waves pass through glass more easily than heat waves.

5. The atoms and molecules that make up all the forms of matter are in constant thermal motion.

6. We know that automation ensures better working conditions in operation.

7. The masers can operate at other frequencies than those used in the microwave region.

8. On that day the radiotelegraph)' was converted from an abstract theoretical problem into a real fact.

9. One positive charge is now called a proton and this charge is equal to that of one electron.

10. The first solar battery demonstrated in 1954 operated with semiconductor crystals similar to those used in transistors.

11. Since that time Maxwell wrote a great number of works which were the results of his experiments and calculations.

12. The antenna for the receiver is constructed in the same manner as that for the transmitter.

7. Translate the following sentences in writing paying attention to the translation of the word that.

For example:

Can you compare the operation of a vacuum triode with that of a semiconductor diode?

– Ты можешь сравнить действие вакуумного диода с действием полупроводникового диода?

1. Can you compare the operation of a vacuum triode with that of a semiconductor triode?

2. Please, compare the emission of a heated cathode with that of a cold cathode.

3. Compare the weight of a vacuum diode with that of a semiconductor diode.

4. Compare the size of a vacuum triode with that of a semiconductor triode.

5. When capacitors are connected in series, the total capacitance is less than that of the smaller capacitor.

6. The amplification factor of a pentode is higher I than that of a tetrode or a triode.

7. Germanium that is free from impurities is called intrinsic germanium.

8. The triode consists of a cathode that emits electrons; a plate or anode that collects the electrons; and a grid that controls the flow of electrons to the plate.

9. The transistor consists of an emitter that supplies electrons, a collector that collects the electrons, and a base that controls the flow of electrons.