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.

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.

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.

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.

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.

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.

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.

   In some countries in which there is very little rain at any time, the farmers have to irrigate their fields. Irrigation is easy enough if there is a great river near the crops, and if there is plenty of water in it. Canals carry the river water to the fields when necessary. In some seasons there may be too much water in the river, and the water may flood all the land near it. At other times the river water may not be enough for all the farmers, and then it will be difficult to irrigate the fields.

   To prevent these difficulties, a dam may be built across the river. This will store water for dry seasons, and in wet seasons it will prevent the flooding of the land. A great lake will, no doubt, be formed behind the dam, and this may mean that houses and fields will be covered with water. Most people will accept that and will be ready to move to other places. Then the country can have the right amount of water at all times; more crops will be grown, there will be more food for everyone, and there will be no more floods.

   Dams have been built for centuries in different parts of the world. Modern dame are usually built of concrete（混凝土）but earth dams were used in India and Sri Lanka about 2500 years ago. There was another across the River Tigris very long ago, and large numbers of irrigation canals were made in Iraq to irrigate the land. The Romans were great dam-builders and there was also a famous dam at Ma’ rubin Arabia.

   We cannot use sea water for irrigation; the salt will not allow the crops to grow. Fresh water is always needed, and it is very difficult and costly to make fresh water from sea water. This is done in a few countries, but the fresh water is for drinking. There is not enough at present for irrigation. Perhaps a scientist will one day invent a cheaper way of producing fresh water from the sea.

1．The first paragraph mainly talks about          .

      A．the problems caused by river water      

       B．the necessity to irrigate the field

      C．the water shortage in some countries    

       D．the canals carrying water to fields

2．A dam is usually built          .

      A．to cover the houses and fields              

B．for people to have the right amount of water at all times

      C．to grow crops better

      D．to form a large lake

3．The underlined word“that”means         .

      A．a dam will be built across the river        

       B．a dam will store water for dry seasons

      C．in wet seasons a dam will prevent the flooding of the land

      D．houses and fields will be covered will water

4．The third paragraph suggests that         .

      A．modern dams are made of concrete      

       B．Romans once built many great dams

      C．there was too much water in 1rap in the past

D．modern dams are better than early dams