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Passage 3 Most scientists blame people, at least in part, for global warming. Now, some researchers say people may be partly to blame for the cooling of Antarctica as well. While average global temperatures have risen about one degree Fahrenheit over the past century, Antarctica over all appears to have cooled slightly in the past few decades. That has been puzzling, because the polar regions are thought to be more sensitive to warming trends than the rest of the globe. Even more puzzling, a small portion of Antarctica--the peninsula that stretches north toward South America--defies the cooling trend. It has been warming very rapidly, about five degrees over the past 50 years, 10 times the global average. Writing in today’ s issue of the journal Science, Dr. David Thompson, a professor of atmospheric science at Colorado State University, and Dr. Susan Solomon, a senior scientist at the National Oceanic and Atmospheric Administration in Boulder, Colo., argue that the ozone hole, which has opened up each spring over Antarctica in recent years, may help explain both contradictory trends. A vortex of winds continually blows around Antarctica, tending to trap cold air at the South Pole. In the new paper, Dr. Thompson and Dr. Solomon show that the winds have strengthened in the past few decades, keeping the cold air even more confined. The peninsula, which lies outside the wind vortex, escapes the cooling effect, the scientists said. They say the ozone hole may be the cause of the stronger winds. Close to the ground, ozone, a molecule consisting of three oxygen atoms, forms a large and unhealthy component of smog. High in the atmosphere, however, nature occurring ozone is essential for life, blocking ultraviolet rays that would fatally mangle DNA. However, fewer ozone molecules mean the atmosphere absorbs less ultraviolet radiation. Instead of warming the air, the rays bounce off the snow and ice of Antarctica and reflect back into space. Scientists already knew that the ozone hole had cooled the upper atmosphere. Dr. Thompson and Dr. Solomon show that the troposphere, the lowest six miles of the atmosphere, has also cooled. "It’ s a lot of food for thought in there," said Dr. John Walsh, a professor of atmospheric science at the University of Illinois and an author of a paper in Science in January that indicated Antarctica was cooling. He noted that the ozone hole was usually largest in November or December, but that the greatest cooling had been about six months later. The author of the passage is mainly concerned with ______ .
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在行政诉讼的二审程序中，行政机关可以改变原具体行政行为。 ( )
自由竞争时期，资本主义国家对外经济联系的主要方式是商品输出。 ( )
In 1971 there were about 3,700 million people in the world. If the population were (21) evenly over the earth’ s surface there would be about 50 people to the square mile; but there are vast areas of desert and mountain and tropical forest (22) are uninhabited, (23) at the other (24) , in the great cities millions may live within a few square miles. (25) of the world’ s population is concentrated on only a small (26) of the earth’ s land surface, in the rich valleys and (27) plains, because people up to the present time have (28) to congregate in place where the climate and soil make it easy to grow food and obtain shelter. A (29) world population and the discoveries of science (30) this pattern of distribution in the future. As men slowly learn to master diseases, control floods, prevent famines, and stop wars, fewer people die every year; and in (31) the population of the world is steadily (32) . When numbers (33) , the extra mouths must be fed. New lands must be brought (34) cultivation, or land already (35) , made to yield larger crops. In some areas the accessible land is largely so intensively cultivated (36) it will be difficult to make it (37) more food. in some areas the population is so dense that the land is divided into. units (38) tiny to allow for much improvement in farming methods. (39) a large part of this farming population drawn (40) into industrial occupations, the land might be farmed much more productively by modern methods.
Task 5 Conversation: The following are two business letters. After reading them, you should give brief answers to the 5 questions (No. 56 through No. 60) that follow. The answers should be no more than 3 words. They should be written after the corresponding numbers on the Answer Sheet. Letter OneDear Sirs, On 5th October I bought one of your expensive "Apollo" fountain pens from Julian’s, a big department store of this town. Unfortunately I have been unable to use the pen because it leaks and fails to write without making blots. I am very disappointed with my purchase. On the advice of Julian’s manager I am returning the pen to you and enclose it with this letter for correction of the fault. Please arrange for the pen to be fixed or replace it with a new one and send it to me as soon as possible. Letter TwoDear Sirs, Thank you for your letter of 9th October enlosing the defective "Apollo" fountain pen, received today. We very much regret that the pen you bought has given you trouble. Normally each of our pens is individually examined before being passed into store and it is hard to understand why this one escaped examination. We have passed your pen to our quality control department for inspection and report. Meanwhile, we are arranging to replace your pen with a new one. We extend our apologies for the inconvenience this matter has caused you, but are confident that the replacement pen you will be receiving will prove satisfactory. What is his requirement about the settlement of the pen He expect the pen to be ______.
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