Passage Fourteen
Antarctica has actually become a kind of space station a unique observation post for detecting important changes in the worlds 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.
Antarctica: Earths 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.
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.
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.
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.
GMAT数学备考经验总结(I)
GMAT数学备考指导:概率问题
巧解GMAT数学求余数问题
详解GMAT数学考试高分策略
GMAT数学考试晋级技巧之:几何问题
GMAT数学常用术语大盘点(一)
GMAT数学考试常用理论总结
非常实用的GMAT数学解题技巧推荐
GMAT数学备考技巧小结
GMAT数学备考指导:整数及余数相关概念
GMAT数学备考指导:五大数学思想的应用
GMAT数学考试中问题求解题型的解题思路
GMAT数学常用词汇及概念汇总(三)
浅析GMAT数学考试应对技巧
GMAT数学常用词汇及概念汇总(五)
GMAT数学备考指导:常用理论小结
掌握方法巧解GMAT数学求余数题型
GMAT数学精华题型解析(8)
GMAT数学常用概念总结
GMAT数学常用词汇及概念汇总(八)
GMAT数学精华题型解析(7)
GMAT数学备考指导:一元二次方程
提高GMAT数学成绩需要掌握哪些技巧
GMAT数学精华题型解析(3)
GMAT考试突破之旅:GMAT数学
GMAT数学题型分析:数据充分性问题
GMAT数学精华题型解析(2)
GMAT数学备考经验谈
GMAT数学常用词汇及概念汇总(二)
GMAT考试牛人谈备考心得:数学及作文
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |