Задание 9. Переведите текст на русский язык. Satellite Telephone Communication.

The new satellite telephone systems combine some of the attributes of cellular telephone systems with those of traditional satellite communications networks. Conventional cellular telephony uses a band of radio waves with frequencies between 800 and 900 million cycles per second (megahertz). (The newer personal communications services, or PCS, operate at about twice this frequency, but both systems function in the same manner). The area to be served is divided into "cell", each with a base station and radio tower. To keep the transmit and receive signals separate, cell phones transmit to the nearest base station on one frequency and receive from it on a different frequency.

The number of subscribers to cellular services has grown so large in the U.S. and elsewhere that systems are being upgraded with digital technology. In traditional networks the speaker's voice is impressed onto the transmitted radio wave by varying the wave's frequency, a technique known as frequency modulation. The problem with this method is that the transmitted signal entirely occupies a piece of radio-frequency bandwidth, or channel, that is 30 kilohertz wide. To provide more capacity, engineers are seeking to make more efficient use of the channels. Therefore, many systems are now being modified to operate with phones in - which the speaker's voice is converted to a stream of digital bits before being transmitted. The data can then be "compressed" prior to transmission, reducing the amount of time each transmission occupies the channel, at the price of a slight loss of signal quality.

Digital transmission of voice signals is also employed in the conventional (or "public switched") telephone network but at much higher rates - 64 kilobits per second, as opposed to the eight kilobits per second typical of digital cellular systems. Digital sampling at such a high rate ensures good quality but requires even more bandwidth that transmitting the analog signal itself. S why bother to do it? Because it affords an easy method of merging many telephone calls onto a single fiber-optic cable or microwave link, as the individual data streams can be multiplexed together into one, higher-rate stream, which in turn can be merged with others into still higher-rate streams. Also, with digital signals it is easier to remedy any impairment encountered in the network, because each bit can be restored if, for example, its amplitude were corrupted in some fashion.

The local central office switches are connected together (usually via fiber-optic cables) to even larger "toll" switches that handle the long-distance calls. Calls going overseas are routed to special international switches, from which they are then carried over undersea fiber-optic cables or via satellite.

Вариант 17

Задание 1. Измените число существительных с единственного на множественное и внесите соответствующие изменения в остальные члены предложений.

1. The roof of that house leaks, it needs repairing.

2. The child saw a sheep in the field.

3. A passer-by saw the accident.

4. Put this knife on that table.

5. He is putting on his coat.

6. This program will be shown by him.

Задание 2. Измените форму прилагательных, данных в скобках, и переведите предложения на русский язык.

1. This piece of homework is (bad) than your last one.

2. This piece of homework is (bad) you have ever done.

3. Richard is not as (tall) as Tom.

4. Tom is (tall) than Richard.

5. Tom is the (tall) boy in the class:

6. Athens is (far) from London than Rome is.

Задание 3. Вставьте модальные глаголы may, can, must, need.

1.... he ride a bike?

2. If you want to be healthy, you ... drink much coffee.

3. ... I take a sweet? Yes, of course.

4. You ... choose any instrument if you like.

5. You ... learn music.

6. ... I listen to the music?

Задание 4. Поставьте глаголы, данные в скобках, в нужную форму.

1. If you (not to listen) to the radio, please (to switch) it off.

2. Somebody (to drink) my coffee! My cup was full.

3. The robbers (to steal) the car and they (to drive) away.

4. But last January I (to read) a book about Russian travelers.

5. We (to live) next door to each other since Alison (to move) to London.

6. Dan (to get) a fax from Boston an hour ago, but he not (to answer) it yet.

Задание 5. Переведите предложения на английский язык.

1. Мой брат никогда не носит шляпу лету.

2. Боюсь, я проиграл эту партию в шахматы (this game of chess). Я играл очень плохо. Обычно я играю намного лучше.

3. Я не играл в футбол с 1983 года.

4. Он писал письмо, когда я увидел его.

5. Как только я начал интересоваться своей работой, мне нужно было идти домой.

6. Петр обычно делает домашнее задание перед ужином.

Задание 6. Образуйте отрицательную и вопросительную формы предложений.

1. He discusses many questions at the office.

2. They have sent us several telegrams lately.

3. The tourists were not allowed to attend the sitting of the Parliament.

4. I was to wait for her at the railway station.

5. He will be working at the library at this time tomorrow.

Задание 7. Задайте вопросы к каждому члену предложения.

1. We discussed this problem last week.

2. The weather was very bad and the passengers had to wait at the airport.

3. You must be at home by 11 o'clock.

4. My doctor prescribed me this medicine.

5...The agreement will be reached by them tomorrow.

Задание 8. Задайте общий, специальный, альтернативный и разделительный вопросы к каждому предложению.

1. I was repairing my car the whole day yesterday.

2. My friend knows Spanish very well.

3. Yesterday I came home at 3 o'clock.

4. The cat is sleeping before the fire.

5. There were three mistakes in my test

Задание 9. Переведите текст на русский язык.