2008年度全国职称外语等级考试试卷及答案（理工类C级）
第4部分：阅读理解（第31～45题, 每题3分, 共45分）
下面有3篇短文, 每篇短文后有5道题。请根据短文内容, 为每题确定1个最佳选项。
第一篇
The Hyper-X
The Hyper-X（超音速飞机）recently broke the record for air-breathing jet planes when it traveled at a Hypersonic speed（超音速）of seven times the speed of sound. That's about 5,000 miles per hour. At this speed, you'd get around the world-flying along the equator（赤道）in less than 5 hours.
The Hyper-X is an unmanned, experimental aircraft just 12 feet long. It achieves hypersonic speed using a special sort of engine known as a scramjet（超音速冲压式喷气发动机）.
For an engine to burn fuel and produce energy, it needs oxygen. A jet engine, like those on passenger airplanes gets oxygen from the air. A rocket engine typically goes faster but has to carry its own supply of oxygen. A scramjet engine goes as fast as a rocket, but it doesn't have to carry its own oxygen supply.
A scramjet's special design allows it to obtain oxygen from the air that flows through the engine. And it does so without letting the fast-moving air put out the combustion（燃烧）flames. However, a scramjet engine works properly only at speeds greater than five times the speed of sound.
A booster rocket（助推火箭）carried the Hyper-X to an altitude of about 100,000 feet for its test flight. The aircraft's record-beating flight lasted just 11 seconds. That brief journey on March 27 makes a major milestone on the way to a new breed of very fast airplanes, says Weber J. A. Dam of the University of Michigan in Ann Arbor. In the future, engineers predict, airplanes equipped with scramjet engines could transport cargo quickly and cheaply to the bank（边缘）of space. Such hypersonic jets could carry passengers anywhere in the world in just a few hours.
Out of the three experimental Hyper-X aircrafts built for NASA, only one is now left The agency has plans for another 11-second hypotonic flight, this time at 10 times the speed of sound.
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第二篇
Stop Eating Too Much
"Clean your plate!" and "Be a member of the clean-plate club!" Just about every kid in the US has heard this from a parent or grandparent. Often, it's accompanied by an appeal: "Just think about those starving orphans（孤儿）in Africa!" Sure, we should be grateful for every bite of food. Unfortunately, many people in the US take too many bites. Instead of staying "clean the plate", perhaps we should save some food for tomorrow.
According to news reports, US restaurants are partly to blame for the growing bellies （肚子）. A waiter puts a plate of food in front of each customer, with two to four times the amount recommended by the government, according to a USA Today story. Americans traditionally associate quantity with value and most restaurants try to give them that. They prefer to have customers complain about too much food rather than too little.
Barbara Rolls, a nutrition（营养）professor at Pennsylvania State University, told USA Today that restaurant portion sizes began to grow in the 1 970s, the same time that the American waistline（腰围）began to expand.
Health experts have tried to get many restaurants to serve smaller portions. Now, apparently, some customers are calling for this too. The restaurant industry trade magazine QSR reported last month that 57 percent of more than 4,000 people surveyed believed restaurants served portions that were too large; 23 percent had no opinion; 20 percent disagreed. But a closer look at the survey indicates that many Americans who can't afford fine dining still prefer large portions. Seventy percent of those earning at least $150,000 per year prefer smaller portions; but only 45 percent of those earning less than $25,000 want smaller.
It's not that working class Americans don't want to eat healthy. It's just that, after long hours at low-paying jobs, getting less on their plate hardly seems like a good deal. They live from paycheck（薪金支票）to paycheck, happy to save a little money for next year's Christmas presents.
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第三篇
Sunspots
It's not surprising that sunspots（太阳黑子）were observed by ancient astronomers（天文学家）. The largest sunspots on the sun can be seen without a telescope. It was not until the. invention of the telescope（望远镜）in the early 17th century, however, that systematic studies of sunspots could be undertaken. The great astronomer Galileo was among the first to make telescopic observations of sunspots.
Sunspots are regions of extremely strong magnetic fields（磁场）found on the sun's surface. A sunspot has a dark central core known as the umbra. The umbra is surrounded by a dark ring called the penumbra, where the magnetic field spreads outward. Sunspots appear dark because they are giving off less radiation. They are cooler than the rest of the sun's Surface.
Sunspots are frequently observed in pairs or in paired groups. The members of a spot pair are identified as the leading spot and the following spot. They are identified by their position in the pair in terms of the direction in which the sun rotates（旋转）.
The number of sunspots at any one time varies. A large spot group may consist of as many as 10 groups and 300 Spots across the Sun. The number of spots changes in a fairly regular pattern called the sunspot cycle. The largest number occurs about every 11 years. At sunspot minimum, there are at most just a few small spots.
The average lifetime of an individual spot group is roughly one solar rotation, which is about 25 days. The most persistent large spots, however, can survive for two to three months
41. Careful observations and systematic studies of sunspots
A. were made by ancient astronomers.
B. started in the early 17th century.
C. were made by Galileo only.
D. could be made without a telescope.
42. Sunspots are cooler than the rest of the sun's surface because
A. they produce less energy.
B. they are buried in the sun.
C. they are far away from magnetic fields.
D. they are close to magnetic fields.
43. The leading spot and the following spot are the names of
A. two large sunspots.
B. a large spot and a small spot.
C. the two spots in a spot pair.
D. the central core and the ring around it.
44. If an intense sunspot activity-had occurred in 1857, the next one would have been in
A. 1858. B. 1862. C. 1865. D. 1868.
45. In the last paragraph the word "persistent" means
A. important B. effective. C. enduring. D. visible.