Cables are playing a very important part in today’s communicates. They have been in use for over 100 years, but in the early times they caused a lot of difficulties for the forerunners. Clearly, mess 题目和参考答案——青夏教育精英家教网—

题目内容

Cables are playing a very important part in today’s communicates. They have been in use for over 100 years, but in the early times they caused a lot of difficulties for the forerunners.

Clearly, messages can be sent across the land by means of the electric telegraph, but you cannot put up a line of telegraph posts across the sea. Messages can be sent across the ocean by radio or by cable. The cable lies on the sea bottom and it has to have very good insulation （绝缘）. If any part of it is weak, the water will get through and stop all signals.

The first cable under the sea was between England and France. It was laid in 1851. In 1851 engineers tried to lay cable across the Atlantic Ocean, but they met a lot of diffidently. Half way accrues the Atlantic the cable broke, and the ship that was laying it had to return.

Kclvin advised that another cable ought to be laid. It was mad mady and put on board a big ship. Kelvin and his friends traveled with it and after many days of hard work, they reached America without breaking the cable. Keivin himself sent the first message by cable from America in Britain. Unfortunately only 732 messages were sent through this cable before it broke.

The next cable was laid in 1866, and this time there were no problems. The ship that laid it was the Great Eastem, one of the strongest ships that time there were no problems. The ship that laid it was the Great Eastern, one of the strongest ships that have ever been built. On the other hand, it was driven by powerful engines and also by sails.

1．The undersea cable must be made strong enough to prevent .

A．fishes from eating it B．enemy stealing it

C．water getting through it D．others cutting it

2．The undersea cable that Kelvin and his friends laid was between .

A．England and France B．America and England

C．America and France D．England and Britain

3．This passage mainly tells us .

A．how Kelvin laid the cable B．how the scientists discovered the cable

C．the history of the cable in the world D．how do lay the cable in the sea

CBC

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The making of glass is a very old industry—at least 4 500 years old. Glass has many extraordinary qualities and it is frequently being used in new ways. One of the most interesting new uses for glass is in telephone communication. Scientists have developed glass fibers as thin as human hair which are designed to carry light signals. When the light reaches the other end, it is first changed into electrical signals, which are in turn converted(转变) into sound messages. Called light wave communication， the new system was used successfully in an experiment in Chicago in 1977. During the experiment two glass fibers were able to carry 672 conversations at the same time. The light wave cable, containing 144 glass fibers, has the capacity(容量) to carry 50 000 conversations at the same time. The light wave communication system has two important advantages. First the glass fiber cables are smaller and weigh less than copper(铜) cables; second, they cost less.

1. One of the extraordinary qualities of glass is that it can carry_______.

A. any signal 　　　　　　　　　　　　　　　　　　 B. light signals

C. sound signals 　　　　　　　　　　　　　　　　 D. electrical signals

2. Before you can hear a message on the telephone using the new system_______.

A. the light signals have to be changed into electrical sound

B. neither the light nor the electrical signals have to be changed in any way

C. light must first be changed into electrical signals and then into sound

D. electrical signals must first be changed into light signals and then into sound

3. According to the passage the new telephone communication system_______.

A. was put on experiment in 1977

B. had been put into actual use by 1977

C. had been repeatedly experimented before 1977

D. was first put into actual use in 1977

4. From the passage, you can tell that people prefer glass fiber cables to copper cables because_______.

A. glass fiber is easier to make

B. glass fiber is less expensive

C. glass fiber is more up to date

D. glass fiber delivers messages directly

5. Which of the following statements best expresses the main idea of the passage?

A. Light signals have changed the use of glass in industry.

B. Glass fibers have reduced the cost of telephone communication.

C. Glass is very useful because it has many unusual qualities.

D. The use of glass fibers to carry telephone messages is an interesting new development.

阅读下面短文，从每题所给的四个选项(A、B、C、D)中，选出最佳选项。

The making of glass is a very old industry－at least 4, 500 years old．Glass has many extraordinary qualities and it is frequently being used in new ways．One of the most interesting new uses for glass is in telephone communication．Scientists have developed glass fibres as thin as human hair which are designed to carry light signals．When the light reaches the other end, it is first changed into electrical signals, which are in turn converted(转变)into sound messages．Called lightwave communication, the new system was used successfully in an experiment in Chicago in 1977．During the experiment two glass fibres were able to carry 672 conversations at the same time．The lightwave cable, containing 144 glass fibres, has the capacity(容量)to carry 50, 000 conversations at the same time．The lightwave communication system has two important advantages．First the glass fibre cables are smaller and weigh less than copper(铜)cables; second, they cost less．

(1)

One of the extraordinary qualities of glass is that it can carry ________．
[　　]
A．	any signal
B．	light signals
C．	sound signals
D．	electrical signals

(2)

Before you can hear a message on the telephone using the new system ________．
[　　]
A．	the light signals have to be changed into electrical sound
B．	neither the light nor the electrical signals have to be changed in any way
C．	light must first be changed into electrical signals and then into sound
D．	electrical signals must first be changed into light signals and then into sound

(3)

According to the passage the new telephone communication system ________ '
[　　]
A．	was put on experiment in 1977
B．	had been put into actual use by 1977
C．	had been repeatedly experimented before 1977
D．	was first put into actual use in 1977

(4)

From the passage, you can tell that people prefer glass fibre cables to copper cables because ________．
[　　]
A．	glass fibre is easier to make
B．	glass fibre is less expensive
C．	glass fibre is more up to date
D．	glass fibre delivers messages directly

(5)

Which of the following statements best expresses the main idea of the passage?
[　　]
A．	Light signals have changed the use of glass in industry．
B．	Glass fibres have reduced the cost of telephone communication．
C．	Glass is very useful because it has many unusual qualities．
D．	The use of glass fibres to carry telephone messages is an interesting new development．

The first telegraph cable was laid under the sea between England and France in 1850.Cables are much 1 and heavier than telegraph wires.There are a number of reasons for this:one reason is that the salt water of the sea harms 2 telegraph wires,and so they have to be 3 , another is that,because electricity 4 easily through water,wires have to be 5 to prevent electric signals which are passing through them 6 escaping and getting lost in the sea;a third reason is that cables have to be very strong 7 they will break while they are being 8 along the bottom of the sea from a ship sailing on the surface.

The 9 cables that men tried to lay 10 England and America broke and were 11 during storms.At last,after nine years of hard work,the two English-speaking nations of Britain and America were 12 in 1866 by the electric telegraph under the sea.

Later,all the different 13 of the world were joind up by a 14 of cables.It is 15 easy to send a message by cables as it is to 16 an ordinary telegram,and it takes no longer for a message to 17 half way round the world than from one town to the 18 .Every hour of the day and night 19 are being flashed under the ocean to and20 every country in the world.

1. A.thicker B.better C.longer D.larger

2. A.ordinary B.special C.plain D.simple

3. A.raised B.fixed C.protected D.repaired

4. A.comes B.passes C.escapes D.sends

5. A.hid B.circled C.covered D.dressed

6. A.from B.through C.by D.into

7. A.so B.or C.but D.and

8. A.lined B.pulled C.laid D.covered

9. A.best B.most C.first D.thickest

10. A.between B.around C.beside D. among

11. A.cast B.thrown C.drawn D.lost

12. A.fixed B.joined C.met D.mixed

13. A.cities B.countries C.parts D.peoples

14. A.set B.packet C.sort D.network

15. A.very B.so C.as D.not

16. A.make B.send C.use D.write

17. A.find B.travel C.visit D.meet

18. A.next B.second C.last D.another

19. A.news B.pictures C.messages D.telegrams

20．A.out B.in C.from D.off

The making of glass is a very old industry---at least 4,500 years old. Glass has many extraordinary qualities and it is often being used in new ways.

One of the most interesting new uses for glass is in telephone communication. Scientists have developed glass fibers as thin as human hair which are designed to carry light signal. When the light reaches the other end，it is first changed into electrical signals , which are in turn changed into sound messages.

Called lightwave communication, the new system was used successfully in an experiment in Chicago in 1977. During the experiment, two glass fibers were able to carry 672 conversations at the same time. The lightwave cable , containing 144 glass fibers, is able to carry 50,000 conversations at the same time.

The lightwave communication system has two important advantages. First, the glass fiber cables are smaller and weigh less than copper cables. Second, they cost less.

Perhaps it can be said that telephone communication has entered the age of light.

56. According to the passage，people started to make glass ______.

A. 4, 500 years ago B. no less than 4, 500 years ago

C. less than 4, 500 years ago D. nearly 4, 500 years ago

57. One of the extraordinary qualities of glass is that it can carry ______.

A. sound signals B. light signals C. electric signals D. any signals

58. According to the passage the new telephone communication system ______.

A. has been put into actual use B. was put into actual use in 1977

C. was put on experiment in 1977 D. had been repeatedly experimented on before 1977

59. Which of the following statements best expresses the main idea of the passage?

A Glass is very useful because it has many unusual qualities.

B. Light signals have changed the use of glass in industry.

C. Glass fibres have reduced the cost of telephone communication.

D. The use of glass fibres to carry telephone messages is an interesting new development.

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