单选题The Changing Middle Class The United States perceives itself to be a middle-class nation. However, middle class is not a real designation, nor does it carry privileges (特权). It is more of a perception, which probably was as true as it ever could be right after World War Ⅱ. The economy was growing, more and more people owned their own homes, workers had solid contracts with the companies that employed them, and nearly everyone who wanted a higher education could have one. Successful people enjoyed upward social mobility. They may have started out poor, but they could become rich. Successful people also found that they had greater geographic mobility. In other words, they found themselves moving to and living in a variety of places. The middle class collectively holds several values and principles. One strong value is the need to earn enough money to feel that one can determine one"s own economic fate. In addition, middle-class morality (道德观) embraces principles of individual responsibility, importance of family, obligations to others, and believing in something outside oneself. But in the 1990s, those in the middle class found that there was a price for success. A U.S. News long commutes became routine; the need for child care put strains on the family; and public schools were not as good as they once were. Members of the middle class were no longer financing their lifestyles through earnings but were using credit to stay afloat. The understanding of just what middle class meant was changing.

单选题Look on The Bright Side Do you ever wish you were more 1 , someone who always expected to be successful? Having someone around who always fears the 2 isn"t really a lot of fun. We all know someone who sees a single 3 on a sunny day and says, "It looks like rain." But if you 4 yourself thinking such things, it"s important to do something 5 it. You can change your view of life, according to psychologists. It only takes a little 6 , and you"ll find life more rewarding as a 7 . Optimism, they say, is partly about self-respect and confidence, but it"s also a more positive way of looking at life and all it has to 8 . Optimists are more likely to start new projects and are generally more prepared to take 9 . Upbringing is obviously very important in forming your 10 to the world. Some people are brought up to depend too much 11 others and grow up forever 12 other people when anything goes wrong. Most optimists, on the 13 hand, have been 14 not to regard failure as the end of the world—they just 15 with their lives.

单选题Extensive reporting on television has helped to {{U}}bring about{{/U}} interest in a wide variety of sports and activities.

单选题His sincerity added much more credibility to the words.

单选题The Family The structure of a family takes different forms around the word and even in the same society. The family's form changes as it adapts to changing social and economic influences. Until recently, the most common form in North America was the nuclear family, consisting of a married couple with their minor children. The nuclear family is an independent unit. It must be prepared to fend for itself. Individual family members strongly depend on one another. There is little help from outside the family in emergencies. Elderly relatives of a nuclear family are cared for only if it is possible for the family to do so. In North America, the elderly often do not live with the family； they live in retirement communities and nursing homes. There are many parallels between the nuclear family in industrial societies, such as North America, and of families in societies such as that of the Inuits, who live in harsh environments. The nuclear family structure is well adapted to a life of mobility. In harsh conditions, mobility allows the family to hunt for food. For North Americans, the hunt for jobs and improved social status also requires mobility. The nuclear family was not always the North American standard. In a more agrarian time, the small nuclear family was usually part of a larger extended family. This might have included grandparents, mother and father, brothers and sisters, uncles, aunts, and cousins. In North America today, there is a dramatic rise in the number of single-parent households. Twice as many households in the United States are headed by divorced, separated, or nevermarried individuals as are comprised of nuclear families. The structure of the family, not just in North America, but throughout the world, continues to change as it adapts to changing conditions.

单选题The proposal was endorsed by the majority of members.

单选题Julia Margaret Cameron was among the pioneers in a new kind of portrait photography—the close-up.

单选题The policeman went into action {{U}}as soon as{{/U}} they heard the alarm.

单选题This is not typical of English, but is a feature of the Chinese language.

单选题The high-speed trains can have a major impact on travel preferences A. force B. total C. small D. similar

单选题That guy is intelligent but a bit dull .

单选题Her mood can be {{U}}gauged{{/U}}, by her reaction to the most trivial of incidents.

单选题Messalina's name has become a {{U}}byword{{/U}} for notorious behavior.

单选题According to the passage, which of the following is most important in saving declining species?

单选题The book provides a concise analysis of the country's history. A. clean B. perfect C. real D. brief

单选题Parents have a legal duty to ensure that their children are provided with efficient education suitable to their age.

单选题下面的短文有15处空白，请根据短文内容为每处空白确定1个最佳选项。 Where Did All the Ships Go? The Bermuda Triangle is one{{U}} (51) {{/U}}the greatest mysteries of the sea. In this triangular area between Florida, Puerto Rico and Bermuda in Atlantic, ships and airplanes{{U}} (52) {{/U}}to disappear more often than in{{U}} (53) {{/U}}parts of the ocean. And they do so{{U}} (54) {{/U}}leaving any sign of all accident or any dead bodies. It is{{U}} (55) {{/U}}that Christopher Columbus was the first person to record strange happenings in the area. His compass(指南针) stopped working, a flame came down from the sky, and a wave 100 to 200 feet high carried his ship about a mile away. The most famous disappearance in the Bermuda Triangle was the US Naval Air Flight 19.{{U}} (56) {{/U}} December 5,1945, five bomber(轰炸机) planes carrying 14 men{{U}} (57) {{/U}}on a training mission from the Florida coast. Later that day, all communications with Flight 19 were lost. They just disappeared without a trace. The next morning, 242 planes and 19 ships took part in the largest air-sea(海空联合的) search in history . But they found nothing. Some people blamed the disappearances{{U}} (58) {{/U}}supernatural forces. It is suggested the {{U}}(59) {{/U}}ships and planes were either transported to other times and places, kidnapped(诱拐)by aliens{{U}} (60) {{/U}}attacked by sea creatures. There are{{U}} (61) {{/U}}natural explanations, though. The US Navy says that the Bermuda triangle is one of two places on earth{{U}} (62) {{/U}}a magnetic(有磁性的) compass points towards true north {{U}}(63) {{/U}}magnetic north.{{U}} (64) {{/U}}planes and ships can lose their way if they don't make adjustments . The area also has changing weather and is known{{U}} (65) {{/U}}its high waves. Storms can turn up suddenly and destroy a plane or ship. Fast currents could then sweep away any trace of an accident.

单选题Mary {{U}}gets up{{/U}} at the same time every morning.

单选题Flying the Hypert Skies A little airplane has given new meaning to the term "going hyper." The Hyper-X recently broke the record for air-breathing jet planes when it traveled at a hypersonic speed 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 -- 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. It may sound like something from a comic book, but engineers have been experimenting with scramjets since the 1960s. 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 flames. However, a scramjet engine works properly only at speeds greater than five times the speed of sound. A booster rocket 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. Although the little plane's self-powered flight lasted only 11 seconds, that brief journey on March 27 makes a major milestone on the way to a new breed of very fast airplanes, comments Werner J. A. Dahm 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 brink of space. Such hypersonic jets could potentially 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 hypersonic flight, this time at 10 times the speed of the sound.

单选题Soldiers are trained to obey their officer"s orders without question.