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 roar down from the polar plateau to the sea. Left bare are spectacular gorges, rippled fields of sand dunes, clusters of boulders(blG)sculptured 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 that they may carry a message of hope for the verdant(草木繁茂的) parts of the scientists believe that in some cases the dry valleys may soak up pollutants faster than pollutants enter them 21. Antarctica is scientifically important in that A)it is a space station B)it is an ideal place for the investigation of glaciology C) there is the mysterious dry valley D)it can help people detect global environmental changes 22. The reason for the disappearance of glaciers in the dry valley is A)that they've desended to the ross sea B) that they' ve been blasted out by vicious winds C) the global warming trend ever since the ice age D) that they've been changed into gorges, sand dunes and boulders 23. When the author calls Antarctica "distant early warning sensor", he actually means that A)such equipment has been set up for scientific purpose B) the research groups there are like such kind of sensors C)potential global changes can be seen on Antarctica first D)Antarctica is remote from other parts of the earth 24. Which of the following statements is true according to the article A) There is a cluster of island west of the Transantartic Mountain B) Scientific research on Antarctica only centers on the ice and snow there. C)Dry valleys may be a place to dispose of our pollutants D)All the countries on earth should be concerned about the health of the West Antarctic Ice sheet 25. The word "spotted"(2nd paragraph)can best be replaced byperhaps 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 roar down from the polar plateau to the sea. Left bare are spectacular gorges, rippled fields of sand dunes, clusters of boulders(大圆石)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 that they may carry a message of hope for the verdant(草木繁茂的)parts of the earth. Some scientists believe that in some cases the dry valleys may soak up pollutants faster than pollutants enter them. 21.Antarctica is scientifically important in that ____. A) it is a space station B) it is an ideal place for the investigation of glaciology C) there is the mysterious dry valley D) it can help people detect global environmental changes 22.The reason for the disappearance of glaciers in the dry valley is ____. A) that they’ve desended to the Ross sea B) that they’ve been blasted out by vicious winds C) the global warming trend ever since the ice age D) that they’ve been changed into gorges,sand dunes and boulders 23.When the author calls Antarctica “distant early warning sensor”, he actually means that ____. A) such equipment has been set up for scientific purpose B) the research groups there are like such kind of sensors C) potential global changes can be seen on Antarctica first D) Antarctica is remote from other parts of the earth 24.Which of the following statements is true according to the article? A) There is a cluster of island west of the Transantartic Mountain. B) Scientific research on Antarctica only centers on the ice and snow there. C) Dry valleys may be a place to dispose of our pollutants. D) All the countries on earth should be concerned about the health of the West Antarctic Ice Sheet. 25.The word “spotted”(2nd paragraph)can best be replaced by____