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The Centre of Our Galaxy

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On a clear, moonless night the shimmering light of the Milky Way glows especially bright toward the constellation Sagittarius. For years astronomers have been aware, from the distribution of groups of stars and from measurements of stellar motions, that objects in our galaxy must travel in orbits around a centre located in that direction. Astronomers also have found that in most cases other galaxies are especially bright toward the centre because the density of stars increases markedly there. In many instances the central regions also seem to be the sites of intriguing behaviour, including the generation of enormous quantities of energy, peculiar radiations and other unusual effects. More and more, it seems that massive, unimaginably dense objects - black holes - lie at the heart of some of these galaxies. Could our own galaxy also harbour such an exotic object at its centre?

The central region of the Milky Way has fascinated astronomers for many decades. After all, our galactic centre is only about 25,000 light-years away as opposed to millions of light-years for centres of the nearest other galaxies, and so it is the one astronomers might reasonably hope to see and to understand best. Yet for a long time there was no direct way to see the centre of our galaxy or to learn much about it, because it is cloaked in large and dense clouds of gas and dust.

Recent discoveries and new technologies have made it possible at last to study the centre of our own galaxy in some detail. These developments include improved techniques for collecting and analyzing astronomical radio waves and infrared radiation as well as space flights above the earth's atmosphere, which have made possible the detecting of energetic X-ray and gamma-ray radiation emanating from the centre of the galaxy.

 

Ex. 2. Change each sentence into a general question. Answer each question with a short answer.

1. Mrs. Clark and Sarah have been out shopping.

2. They've just returned home.

3. Mrs. Clark has just opened a letter.

4. She has worked as a private secretary for a musician.

5. The musician has stopped working.

6. He has asked her to find another job.

7. The letter has upset Mrs Clark.

8. She has not paid for her new house yet.

9. Sarah has heard the bad news.

10. Mrs Clark has never cried in front of Sarah before.

 

Ex. 3. Add tag-questions to the following statements.

1. He has just returned from a conference on Mars exploration.

2. Since then, little has happened in human space flight.

3. In recent years, a further complicating factor has emerged.

4. They sure haven't let time pass them by, the way some companies did.

5. Theoretical research on GA has resulted in a new scheme.

6. We have stressed transistors in this section.

7. Mathcad has always been known for more than computational excellence.

8. DataPlay system has breached this market with a new version of its Microdrive system.

9. He has taught the gateway course, in all its incarnations.

10. But for one year now I have been with a small business.

Ex. 4. Complete the sentences correctly.

1. This is the first time I (see this film).

2. That's the eighth time you (sing that song) today.

3. This is the only time this week I (feel happy).

4. This is the third serious mistake you (make) in this job.

5. This is the only time I (ever see) her cry.

6. That's the tenth cup of coffee you (drink) since breakfast.

7. It's the first time all the family (be together) since Sue's wedding.

8. This is the best meal I (eat) this year.

9. "Excuse me." "That's the first thing you (say) to me today."

10. These are the first clothes I (buy) myself since Christmas.

Ex. 5. Read the situations and write sentences from the words in brackets.

1. You go to Jill's house but she isn't there. (she/go/out) She has gone out.

2. You come back to your home after many years. It isn't the same as before. (it/change/a lot) _______

3. I invite Rachel to the party but she cаn't come. (she/arrange/to do something else) _______

4. You go to the cinema. You arrive at the cinema late. (the film/already/begin) _______

5. I am very pleased to see Tim again after such a long time. (I/not/see/him for five years) _______

6. I offer Sue something to eat but she isn't hungry (she/just/have breakfast) _______

7. After lunch you go to see a friend at her house. She says "Would you like something to eat?" You say: "No, thank you. (I/just/have lunch) _______"

8. Joe goes out. Five minutes later, the phone rings and the caller says "Can I speak to Joe?" You say: "I'm afraid (she/just/go out) _______"

9. You are eating in a restaurant. The waiter thinks you have
finished and starts to take your plates away. You say: "Wait a minute! I (not/finish/yet) ______"

10. You are going to a restaurant this evening. You phone to reserve a table. Later your friend says: "Shall I phone to reserve a table?" You say: "No, I (already/do/it) _______

11. You know that a friend of yours is looking for a job. Perhaps she has been successful. Ask her: "you/already/find anything? _______"

12. Ann went to the bank, but a few minutes ago she returned. Somebody asks: "Is Ann still at the bank?" You say: "No, (she/just/come back) _______"

 

Ex. 7. Translate into English using the Present Perfect.

1. Я не видел тебя очень давно. Где ты был все это время?

2. Ты уже закончила свою дипломную работу?

3. Я еще не напечатала это письмо.

4. Я знаю профессора с 2000 года.

5. Ты принес эти журналы с собой?

6. Петр закончил университет в этом году.

7. Они приобрели опыт в патентных отделах корпораций.

8. Мы представили простую теоретическую модель, способную объяснить происхождение этого эффекта.

9. Недавняя работа показала, что это ошибочное заключение.

10. Эти электроны, которые вышли из своих атомов, называются свободными электронами.

11. Автор и соавтор многих технических статей, он также написал эти учебники.

12. Космические корабли США посетили все планеты, кроме одной, и их крупнейшие луны.

13. Со времени его запуска в июле 1999 года он является ключом к одному открытию за другим в физике черных дыр.

14. Высококвалифицированная команда инженеров и техников создала необходимое ноу-хау для удержания компании на передовых позициях.

15. Вы видели мою коллекцию компакт-дисков?

16. С тех пор я изменил свою точку зрения.

17. Мы внимательно изучили ваш доклад.

18. Я нахожусь здесь с утра.

 

 




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