Файл: Сибирский государственный университет телекоммуникаций и информатики.doc

We suggested that his project be discussed in detail. 2. The engineer insisted that all the experimental data obtained should be exact. 3. The scientist demanded that the test should be repeated. 4. We were ordered that we should take part in the discussion. 5. The majority of the committee advised that the research work should be postponed. 6. I insisted that she regularly should inform us of the results of her experiments. 7. He suggested that the equipment should be brought in a week. 8. The engineer demanded that the molecules should be heated in order to make them move very rapidly. 9. Brattain and Gidney (the physical chemist of the group) suggested that the semiconductor and the metal plate should be immersed in an electrolyte to overcome the blocking effects of the surface states. 10. He demanded that the process should be modified to fabricate devices with a higher gain performance.

IV. Open the brackets using the Subjunctive Mood.

Model: He (advise) them what to do, but he couldn’t get in touch with them.

He would have advised them what to do, but he couldn’t get in touch with them.

1. I (obtain) a datum quantity for direct current, but the galvanic element that I used failed.

2. The supply voltage must have been increased, more current (flow) through the regulator tube.

3. Why did not you ask them to discuss your problem then? They (not postpone) it.

4. It (be) wise of you to read scientific journals on your profession.

5. I think nobody (object) to discussing the results of our work tomorrow.

6. She (buy) the disk, but she had no money.

7. It (be) impossible to determine the chemical composition of the metal without a laboratory analysis.

8. The heat (cause) mechanical troubles, but fortunately the temperature weren’t raised above a certain limit.

9. I (come) to the meeting, but I wasn’t informed about it.

10. This method is not efficient otherwise it (introduce) long ago.

V. Complete the given phrases using the Subjunctive Mood.

We propose…
They insist…
The speaker demanded…
I suggest …

5. The professor strongly advised …

VI. Translate the sentences with the Subjunctive Mood after the following conjunctions: lest, so that, in order that, though.

1. One of the elements in a vacuum valve must be heated so that it will give off electrons. 2. In order that this method might be applied two conditions must be observed. 3. The sound level of the broadcast program sent to the transmitter must be carefully adjusted in order that the carrier be neither over- nor undermodulated. 4. Electrical conductors are said to be in series if they are connected so that all the current which flows through one conductor must flow through each of the others. 5. Great attention is paid to ecological problems all over the world so that

the air in large cities should be kept clean. 6. You must put down this formula lest you should forget it. 7. Metal parts are tested for defects lest they should fail in operation. 8. All kinds of safety devices for motor cars are being developed lest accidents should occur. 9. The video must be squeezed into a small package in order that it should be transmitted on top of the radio channels without affecting their reception. 10. We employ an asymmetric gate recess scheme lest source resistance and output conductance should be increased. 11. Though the calculations might be very complex, the computer will do them in a few minutes. 12. The digital stream takes up much less capacity in the airwaves, so that the space needed in the past for just one analogue channel can now carry five, six or seven different programs.

VII. Translate the sentences with the Subjunctive Mood after the following conjunctions: as if and as though.

If the elements lie near one another in the electromotive series they behave as if they were of the same chemical species. 2. The distance is not measured on the curved surface of the Earth but is computed as if the line were passing through the Earth. 3. The Earth behaves as though it were an immense magnet. 4. They discussed the subject as though they had studied it before. 5. The fluid motion in the transition region may be treated as if the region were plain. 6. He looks at his new, compact and stylish mobile phone as though he were proud of it. 7. The classroom is so quiet as if there were nobody in it. 8. The mixture is combustible as though the fuel were uniformly mixed with the air. 9. He spoke as if he had been the witness of the incident. 10. A young scientist wrote a great work as if he had a large experience in his field.

VIII. Open the brackets and use the correct form of the Subjunctive Mood.

It seemed as though he (know) it long ago.
He looked as if he (want) to say something but (be) afraid to begin his speech.
It seemed as if he never (hear) of it before.
She speaks English as if she (be) an Englishwoman.
She looked very tired as if she (work) from early morning till night.
He looked pleased as though he (reach) his purpose.
Companies are beginning to show interest in the sector as though they already (calculate) their future revenue.
The telecommunication system is transmitting signals of different frequencies as if the bandwidth (be) high.
The student did the calculations in a few minutes as if they (not be) very complex.
The gauge registers the pressure of the water as if it (act) directly downward.
The weight of a body varied during the experiment as though it (place) in different localities.
The combustible mixture produced a lot of power as if it (compress) to a high pressure before it started to burn.

IX. Comment on the use of tenses in the following sentences after wish and if only.

I wish I could drive a car. 2. If only I could have driven a car when I was young. 3. I wish I would be able to drive a car soon. 4. I wish they had introduced their friends to me at the party. 5. I wish they would introduce their friends to me at the party. 6. I wish you had brought your video camera to the yesterday conference. 7. If only he brought his video camera to the conference. 8. I wish you would bring your video camera tomorrow. 9. If only you had mentioned this fact to me before. 10. I wish you told me everything. 11. Mary wishes she had made a report yesterday. 12. Mary wishes she would make a report at the lecture tomorrow. 13. If only I could speak several languages. 14. I wish I would be able to speak several languages one day. 15. I wish I had spoken Italian when I went to Italy. 16. If only you were better educated you would find a good job.

X. Paraphrase the following sentences using the Subjunctive Mood after the verb wish.

Example: My students are not always in time for class.

I wish my students were always in time for class.

My director is too bossy and demanding.
My brother couldn’t fix our new TV yesterday.
I have too much work to do.
I live far from the university.
We are upset that our plan failed.
The scientist was disappointed that he couldn’t fulfill his experiment.
1 ... 32 33 34 35 36 37 38 39 40

Unfortunately I was not able to do all the calculations yesterday.

The experiment is prepared carefully. I hope I shall get good results.

I do not speak French.

I forgot my PIN number that is why I did not take money out of the ATM.

I cannot afford to buy a car.

I have to attend lectures, but they are so boring.

I missed the bus this morning and was late for work.

I did not print the report yesterday because the electricity was cut off.

I left my umbrella on the bus.

XI. Translate the sentences paying attention to the phrases would rather and had better.

I would rather Ann worked with you. 2. I would rather we had left earlier, than we would not have been caught in the rush hour traffic. 3. I would rather John finished the article before he leaves. 4. I would rather the plumber came tomorrow, because I don’t want to wait around for him today. 5. I would rather they tried to fix the computer themselves before they asked me to do it. 6. Would you rather I called you or sent you a text message? 7. You had better work harder in order to pass your exams. 8. You had better do some revision work. 9. You had better get out your calculator and tot it up. 10. You had better send e-mail instead of writing a letter.

XII. What would you do in the following situations. Express your advice using constructions: would rather and would better.

Model; Your record player is too loud.

You had better turn it down.

You drive too fast.
The student talks too much at the lecture.
Your friend lost his passport.
Your mobile phone is discharged and you don’t have a charging device with you, but you have to make an urgent phone call.
Your brother is going to rent a video for you both to watch. He suggests either a comedy or a horror film.

XIII. Comment on the use of the Subjunctive Mood after the expression It’s high time.

It’s high time you took part in this work. 2. It’s high time you thought of your future. 3. It’s high time you earned your own living. 4. It’s high time you called an electrician. 5. It’s high time you got down to business. 6. It’s high time we provided the solution to the problem. 7. It’s high time we finished the theoretical research and proceeded directly to the experimental stage. 8. It’s high time you finished your project. 9. It’s high time you used flash memory instead of diskette. 10. It’s high time you should realize that times have changed.

XIV. Read the text. Express the main idea of the text. Translate it.

Fibre optics communications

For a long time light has been used to send messages. Our ancestors lit beacons when invaders threatened. A hand-held mirror, the heliograph, was first used by the ancient Greeks to reflect the Sun’s rays and flash coded signals over great distances. And lighthouses and traffic lights use light to warn us of danger. But fibre optics communications is an altogether more sophisticated way of sending messages from one place to another: it makes use of long thin glass fibres along which information is sent as pulses of laser light. Fibre optics communications is now a well-established technology and it holds great promise for the future of telecommunications systems. But why should optical fibres be so superior to conventional copper cables? Well, for one thing cables made from optical fibres are cheaper, lighter and easier to install than copper cables. Furthermore, they are completely free from electromagnetic interference since data on a light beam cannot be corrupted by electrical machinery, thunderstorms and “noisy” power lines. Consequently, there is no interference or “cross-talk” between neighbouring fibres, a quality that also means that signals carried by optical fibres are much less liable to be detected compared with electrical signals in copper cables, i.e. the information is effectively secure from eavesdroppers. Safety, too, is an important reason for using optical fibres since broken fibres are not a fire hazard as the escaping light is harmless. The strongest justification for using optical fibres is their potential for carrying considerably more information than copper cables. Since light waves have frequencies about 10000 times higher than the highest frequency radio waves, considerably greater bandwidth is available. Indeed conventional copper cables are hard pressed to keep up with the mounting speed of development in communications and information technology. However, before fibre optics communications could become a reality, two high technology inventions, the laser and low-loss fibre optic cable were needed. By “low loss” is meant glass so pure you could see through a 35 km thick block of it as clearly as through a window pane! Such high purity means that information travels through optical fibres for long distances without having to be repeatedly amplified on the way – it is said to have low attenuation. The raw material for such optically clean fibres is a special kind of sand called silica. An optical fibre is a solid rod of silica, finer than a human hair and surprisingly flexible. It is manufactured in the cleanest of atmospheres to ensure that no speck of dust or fingerprint can mar its purity. The basic construction of an optical fibre comprises a glass core totally enclosed by a glass cladding. A plastic coating covers the cladding and core to prevent dust and moisture from reaching the glass core. Light is guided along the core by being reflected back from the outer cladding to the core, bouncing along from side to side of the core. No light is lost as it bounces from the cladding; at each bounce it is all reflected back to the core. What makes this happen is the relative optical properties of the core and the cladding. The cable is designed so that the refractive index of the core is higher than the refrective index of the cladding. This ensures that light meeting the boundary between the core and cladding at an angle greater than a certain “critical” angle is totally reflected back into the core. This is called total internal reflection. A fibre optics cable is an armoured cable designed both to protect the bundle of fibres from contact with moisture and chemicals, and to strengthen it. Two light sources (or transmitters) are eminently suitable for the job of sending pulses of light down these slender optical fibres: light-emitting diodes (LEDs) and injection-laser diodes (ILDs). Both sources generate light when excited by electricity, and they are the only sources of light capable of being switched on and off fast enough to be modulated by low power analogue or digital signals. Their physical dimensions are compatible with optical fibres and they have the reliability and long life needed in telecommunications systems. Gallium arsenide (GaAs), gallium aluminium arsenide (GaAlAs) and gallium indium arsenide phosphide (GaInAsP) are the materials used in their construction. They convert electricity in to infrared energy efficiently, and the special glass used in fibre optics is more transparent at infrared wavelengths. Infrared LEDs are suitable for use with stepped-index multi-mode fibres since they emit a relatively wide beam of light with a fairy large spectral bandwidth. ILD sources radiate a much narrower beam of infrared with a much narrower spectral width. It is desirable that ILD sources should be used with stepped-index mono mode fibres. Furthermore, ILDs can launch between 0.5mW to 5mW of infrared power into a fibre, compared with the smaller 0.05μmW to 0.3μmW for an LED. GaAlAs ILDs and LEDs generate infrared in the 0.8μm to 0.9μm range, while GaInAsP devices generate infrared in the 1.3m to 1.6m range where attenuation and dispersion by fibres is very low. A photodiode is generally used to convert the modulated infrared light back into electrical signals at the end of the fibre. The photodiode is reverse-biased so that when it absorbs infrared, a small current flows between its cathode and anode terminals. The current is virtually proportional to the amount of light it absorbs. Photodiodes are generally based on silicon. Infrared emitting diodes and photodiodes are available as spectrally-matched pairs: the LED emits maximum infrared radiation at the wavelength to which the photodiode is most sensitive. This wavelength is typically 0.9μm.

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Файл: Сибирский государственный университет телекоммуникаций и информатики.doc

III. Translate the sentences, paying attention to the Subjunctive Mood after verbs: to order, to insist, to demand, to suggest, to advice.

IV. Open the brackets using the Subjunctive Mood.

Model: He (advise) them what to do, but he couldn’t get in touch with them.

He would have advised them what to do, but he couldn’t get in touch with them.

1. I (obtain) a datum quantity for direct current, but the galvanic element that I used failed.

2. The supply voltage must have been increased, more current (flow) through the regulator tube.

3. Why did not you ask them to discuss your problem then? They (not postpone) it.

4. It (be) wise of you to read scientific journals on your profession.

5. I think nobody (object) to discussing the results of our work tomorrow.

6. She (buy) the disk, but she had no money.

7. It (be) impossible to determine the chemical composition of the metal without a laboratory analysis.

8. The heat (cause) mechanical troubles, but fortunately the temperature weren’t raised above a certain limit.

9. I (come) to the meeting, but I wasn’t informed about it.

10. This method is not efficient otherwise it (introduce) long ago.

V. Complete the given phrases using the Subjunctive Mood.

We propose…

They insist…

The speaker demanded…

I suggest …

5. The professor strongly advised …

VI. Translate the sentences with the Subjunctive Mood after the following conjunctions: lest, so that, in order that, though.

VII. Translate the sentences with the Subjunctive Mood after the following conjunctions: as if and as though.

VIII. Open the brackets and use the correct form of the Subjunctive Mood.

It seemed as though he (know) it long ago.

He looked as if he (want) to say something but (be) afraid to begin his speech.

It seemed as if he never (hear) of it before.

She speaks English as if she (be) an Englishwoman.

She looked very tired as if she (work) from early morning till night.

He looked pleased as though he (reach) his purpose.

Companies are beginning to show interest in the sector as though they already (calculate) their future revenue.

The telecommunication system is transmitting signals of different frequencies as if the bandwidth (be) high.

The student did the calculations in a few minutes as if they (not be) very complex.

The gauge registers the pressure of the water as if it (act) directly downward.

The weight of a body varied during the experiment as though it (place) in different localities.

The combustible mixture produced a lot of power as if it (compress) to a high pressure before it started to burn.

IX. Comment on the use of tenses in the following sentences after wish and if only.

X. Paraphrase the following sentences using the Subjunctive Mood after the verb wish.

Example: My students are not always in time for class.

I wish my students were always in time for class.

My director is too bossy and demanding.

My brother couldn’t fix our new TV yesterday.

I have too much work to do.

I live far from the university.

We are upset that our plan failed.

The scientist was disappointed that he couldn’t fulfill his experiment.

Unfortunately I was not able to do all the calculations yesterday.

The experiment is prepared carefully. I hope I shall get good results.

I do not speak French.

I forgot my PIN number that is why I did not take money out of the ATM.

I cannot afford to buy a car.

I have to attend lectures, but they are so boring.

I missed the bus this morning and was late for work.

I did not print the report yesterday because the electricity was cut off.

I left my umbrella on the bus.

XI. Translate the sentences paying attention to the phrases would rather and had better.

XII. What would you do in the following situations. Express your advice using constructions: would rather and would better.

Model; Your record player is too loud.

You had better turn it down.

You drive too fast.

The student talks too much at the lecture.

Your friend lost his passport.

Your mobile phone is discharged and you don’t have a charging device with you, but you have to make an urgent phone call.

Your brother is going to rent a video for you both to watch. He suggests either a comedy or a horror film.

XIII. Comment on the use of the Subjunctive Mood after the expression It’s high time.

XIV. Read the text. Express the main idea of the text. Translate it.

Fibre optics communications

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