Passage Fourteen(Antarctica and Environment)

Antarctica has actually become a kind of space station – a unique observation post for detecting important changes in the world’s environment. Remote from major sources of pollution and the complex geological and ecological systems that prevail elsewhere, Antarctica makes possible scientific measurements that are often sharper and easier to interpret than those made in other parts of the world.

Growing numbers of scientists therefore see Antarctica as a distant-early-warning sensor, where potentially dangerous global trends may be spotted before they show up to the north. One promising field of investigation is glaciology. Scholars from the United States, Switzerland, and France are pursuing seven separate but related projects that reflect their concern for the health of the West Antarctic Ice Sheet – a concern they believe the world at large should share.

The Transantarctic Mountain, some of them more than 14,000 feet high, divide the continent into two very different regions. The part of the continent to the “east” of the mountains is a high plateau covered by an ice sheet nearly two miles thick. “West” of the mountain, the half of the continent south of the Americas is also covered by an ice sheet, but there the ice rests on rock that is mostly well below sea level. If the West Antarctic Ice Sheet disappeared, the western part of the continent would be reduced to a sparse cluster of island.

While ice and snow are obviously central to many environmental experiments, others focus on the mysterious “dry valley” of Antarctica, valleys that contain little ice or snow even in the depths of winter. Slashed through the mountains of southern Victoria Land, these valleys once held enormous glaciers that descended 9,000 feet from the polar plateau to the Ross Sea. Now the glaciers are gone, perhaps a casualty of the global warming trend during the 10,000 years since the ice age. Even the snow that falls in the dry valleys is blasted out by vicious winds that roars down from the polar plateau to the sea. Left bare are spectacular gorges, rippled fields of sand dunes, clusters of boulders sculptured into fantastic shapes by 100-mile-an-hour winds, and an aura of extraterrestrial desolation.

Despite the unearthly aspect of the dry valleys, some scientists believe they may carry a message of hope of the verdant parts of the earth. Some scientists believe that in some cases the dry valleys may soak up pollutants faster than pollutants enter them.

1.What is the best title for this passage?

A.Antarctica and environmental Problems.

B.Antarctica: Earth’s Early-Warning station.

C.Antarctica: a Unique Observation Post.

D.Antarctica: a Mysterious Place.

2.What would the result be if the West Antarctic Ice Sheet disappeared?

A.The western part of the continent would be disappeared.

B.The western part of the continent would be reduced.

C.The western part of the continent would become scattered Islands.

D.The western part of the continent would be reduced to a cluster of Islands.

3.Why are the Dry Valleys left bare?

A.Vicious wind blasts the snow away.

B.It rarely snows.

C.Because of the global warming trend and fierce wind.

D.Sand dunes.

4.Which of the following is true?

A.The “Dry Valleys” have nothing left inside.

B.The “Dry Valleys” never held glaciers.

C.The “Dry Valleys” may carry a message of hope for the verdant.

D.The “Dry Valleys” are useless to scientists.

B

    The fiddler crab (蟹) is a living clock. It indicates the time of day by the colour of its skin, which is dark by day and pale by night. The crab’s changing colour follows a regular twenty-four hour plan that exactly matches the daily rhythm of the sun.

    Does the crab actually keep time, or does its skin simply answer to the sun’s rays, changing colour according to the amount of light which strikes it? To find out, biologists kept crabs in a dark room for two months. Even without daylight, the crab’s skin colour continued to change exactly on time.

    This characteristic probably developed gradually in answer to the daily rising and setting of the sun, to help protect the crab from sunlight and enemies. After millions of years it has become completely controlled inside the living body of the crab.

    The biologists noticed that once each day the colour of the fiddler crab is especially dark, and that each day this happens fifty minutes later than on the day before. From this they discovered that each crab follows not only the rhythm of the sun but also that of the tides (潮水). The crab’s period of greatest darkening is exactly the time of low tide on the beach where it was caught!

40. The crab’s changing colour _______.

A. tells the crab what time it is 

B. protects the crab from the sunlight and enemies

C. keeps the crab warm            

D. is of no real use

41. When the fiddler crabs were kept in the dark, they _______.

  A. did not change colour          B. changed colour more quickly

  C. changed colour more slowly     D. changed colour on the same timetable

42. The crab’s colour—changing ability was probably developed _______.

   A. in the process of evolution (进化)    B. over millions of years

   C. by the work of biologists           D. both A and B  

43. The best title for this selection would be _______.

   A. The Sun and the Tides              B. Discoveries in Biology

   C. A scientific Study                  D. A Living Clock

 D

Sydney—Mobile phone has become a problem for middle schools. Some middle schools in Australia have banned students from carrying mobile phones during school hours.

Mobile phone use among children has become a problem for the school this year. Several children have got mobile phones as Christmas gifts, and more students want them.

Mary Bluett, an official, said mobile phone use is a distraction (分心的事) to students during school hours and it also gives teachers so much trouble in their classrooms. Teachers were also saying that sometimes students might use phone messages to cheat during exams.

She said some schools had tried to ban mobile phones. Some parents felt unhappy because they couldn’t get in touch with their children.

Many teachers said students should not have mobile phones at school, but if there was a good reason, they could leave their phones at school offices. They also said there were many reasons why the students should not have mobile phones at school: they were easy to lose and were a distraction from studies.

Many people say that they understand why parents would want their children to have phones, but they think schools should let the students know when they can use their mobile phones.

78. We know from the passage that some children get mobile phones from          .

   A. the makers and sellers                       B. their parents and friends

   C. some other strangers                             D. some mobile phone users

79. Some parents felt unhappy because they couldn’t_________during school hours.

   A. use their mobile phones                      B. leave their mobile phones

   C. help the teachers with their work              D. get in touch with their children

80. The underlined word “they” in the fifth paragraph refers to_______.

   A. mobile phones                                 B. some messages

   C. many teachers                                           D. some students

81. The topic mainly talked about in the text is___________.

   A. when the students of some Australian schools can use their mobile phones

   B. why the students should not use mobile phones in some Australian schools

   C. whether the Australian students can have mobile phones at school

   D. how some parents feel when their children should not carry mobile phones

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