单选题During the SARS period, it is especially important to {{U}}ventilate{{/U}} the room.

单选题When Liam McGee departed as president of Bank of America in August, his explanation was surprisingly straight up. Rather than cloaking his exit in the usual vague excuses, he came right out and said he was leaving to pursue my goal of running a company. Broadcasting his ambition was "very much my decision," McGee says. Within two weeks, he was talking for the first time with the board of Hartford Financial Services Group, which named him CEO and chairman on September 29. McGee says leaving without a position lined up gave him time to reflect on what kind of company he wanted to run. It also sent a clear message to the outside world about his aspirations. And McGee isn"t alone. In recent weeks the No. 2 executives at Avon and American Express quit with the explanation that they were looking for a CEO post. As boards scrutinize succession plans in response to shareholder pressure, executives who don"t get the nod also may wish to move on. A turbulent business environment also has senior managers cautious of letting vague pronouncements cloud their reputations. As the first signs of recovery begin to take hold, deputy chiefs may be more willing to make the jump without a net. In the third quarter, CEO turnover was down 23% from a year ago as nervous boards stuck with the leaders they had, according to Liberum Research. As the economy picks up, opportunities will abound for aspiring leaders. The decision to quit a senior position to look for a better one is unconventional. For years executives and headhunters have adhered to the rule that the most attractive CEO candidates are the ones who must be poached. Says Korn Ferry, senior partner Dennis Carey: "I can"t think of a single search I"ve done where a board has not instructed me to look at sitting CEOs first." Those who jumped without a job haven"t always landed in top positions quickly. Ellen Marram quit as chief of Tropicana when the business became part of PepsiCo (PEP) a decade ago, saying she wanted to be a CEO. It was a year before she became head of a tiny Internet-based commodities exchange. Robert Willumstad left Citigroup in 2005 with ambitions to be a CEO. He finally took that post at a major financial institution three years later. Many recruiters say the old disgrace is fading for top performers. The financial crisis has made it more acceptable to be between jobs or to leave a bad one. "The traditional rule was it"s safer to stay where you are, but that"s been fundamentally inverted," says one headhunter. "The people who"ve been hurt the worst are those who"ve stayed too long."

单选题 A Biological Clock Every living thing has what scientists call a biological clock that controls behavior. The biological clock tells {{U}} {{U}} 1 {{/U}} {{/U}}when to form flowers and when the flowers should open. It tells {{U}} {{U}} 2 {{/U}} {{/U}}when to leave the protective cocoons and fly away, and it tells animals and human beings when to eat, sleep and wake. Events outside the plant and animal {{U}} {{U}} 3 {{/U}} {{/U}}the actions of some biological docks. Scientists recently found, for example, that a tiny animal changes the color of its fur {{U}} {{U}} 4 {{/U}} {{/U}}the number of hours of daylight. In the short {{U}} {{U}} 5 {{/U}} {{/U}}of winter, its fur becomes white. The fur becomes gray brown in color in the longer hours of daylight in summer. Inner signals control other biological clocks. German scientists found that some kind of internal clock seems to order birds to begin their long migration {{U}} {{U}} 6 {{/U}} {{/U}}twice each year. Birds {{U}} {{U}} 7 {{/U}} {{/U}}flying become restless when it is time for the trip, {{U}} {{U}} 8 {{/U}} {{/U}}they become calm again when the time of the flight has ended. Scientists say they are beginning to learn which {{U}} {{U}} 9 {{/U}} {{/U}}of the brain contain biological clocks. An American researcher, Martin Moorhead, said a small group of cells near the front of the brain {{U}} {{U}} 10 {{/U}} {{/U}}to control the timing of some of our actions. These {{U}} {{U}} 11 {{/U}} {{/U}}tell a person when to {{U}} {{U}} 12 {{/U}} {{/U}}, when to sleep and when to seek food. Scientists say there probably are other biological clock cells that control other body activities. Dr. Moorhead is studying {{U}} {{U}} 13 {{/U}} {{/U}}our biological clocks affect the way we do our work. For example, most of us have great difficulty if we must often change to different work hours. {{U}} {{U}} 14 {{/U}} {{/U}}can take many days for a human body to accept the major change in work hours. Dr. Moorhead said industrial officials should have a better understanding of biological clocks and how they affect workers. He said {{U}} {{U}} 15 {{/U}} {{/U}}understanding could cut sickness and accidents at work and would help increase a factory's production.

单选题Edwin Hubble Edwin Hubble changed our ideas about the universe and how it developed. The work of few other scientists changed our understanding of 【51】 suddenly. He made his most important discoveries in the 1920s. Today, other scientists continue the work he began back then. Edwin Powell Hubble was born in 1889 in Marshfield, Missouri. He 【52】 his early years in the state of Kentucky. Then he moved with his family to Chicago, Illinois. He attended the University of Chicago, taking mathematics and astronomy 【53】 his specialty. As a student, Hubble was also a member of the University''s basketball team and an excellent boxer. Several people urged him 【54】 for the world heavy weight boxing championship after college. Instead he decided to continue his 【55】 . In his first observations from Mount Wilson, California, Hubble used a telescope with one-hundred fifty-two and began 【56】 more and more distant objects. His first great discovery was made 【57】 he recognized a Cepheid variable star. Cepheid variable stars are stars whose brightness changes at regular periods. Hubble then began to observe more details about galaxies. He studied their shapes and brightness. By 1925, he had made enough observations to say that the universe is organized into many shapes and sizes. As stars differ from one another, he said, 【58】 galaxies. According to his observations, the galaxies have a center, and arms of matter that seem to the center like a pinwheel. Other are shaped 【59】 baseballs or eggs. A few have no special 【60】 Hubble proposed a system to describe galaxies by their shape. His system is still used today. He also showed that 【61】 are similar in the kinds of bright objects they contain. All galaxies, 【62】 , are related to each other much as members of a family are related to each other. In the late 1920s, Hubble studied the movement of galaxies through space. His investigation led to the most important 【63】 discovery of the 20th century—the expanding universe. Hubbies discovery 【64】 a major change in our ideas of the universe. The universe had not been quiet and unchanging since the beginning of time, as many people had thought. It was expanding. The expanding often is 【65】 the Big Bang.

单选题Mr. Henley has {{U}}accelerated{{/U}} his sale of shares over the past year. A. held B. expected C. offered D. increased

单选题It was said that after his father's death, he possessed nearly half of his father's wealth,A. wastedB. ownedC. purchasedD. sold

单选题It is understandable that early civilizations blamed storms on the gods.

单选题The word “smog” first appeared in 1952.

单选题We learn from this passage that

单选题Seeing Red Means Danger Ahead The color red often means danger and by paying attention, (51) can be prevented. At railroad crossings, flashing red fights warn cars to stay back. A red light at a traffic intersection tells cars to stop, so (52) don't run into other cars. In the future, the color red also may help prevent danger (53) construction sites. Thanks to new work by engineers, bridge supports or other kinds of materials could one day contain a color-changing material. It will turn red (54) a structure collapses or falls (55) . A tiny molecule may make a big difference in future warning systems. A polymer (56) a color-changing molecule called a mechanophore turns red seconds before it snaps. The technology may one day allow damage to materials or structures to be easily (57) . The secret behind the color-changing material is a particular type of molecule. A molecule is a group of atoms held together by (58) bonds. Molecules come in all shapes and sizes, and make up (59) you can see, touch or feel. How a molecule behaves depends on what kinds of atoms it contains, and how they're held together. When a polymer containing a color-changing molecule called a mechanophore is about to breaks, it produces a color. When a polymer with mechanophore molecules becomes "injured" or (60) , one of the mechanophore bonds breaks and the material turns red. "It's a really simple detection method," says Nancy Sottos, one of the scientists who worked on the project. "We're (61) up this one bond, and it changes color." Sottos and her team tested the color-changing polymers in their lab. The test (62) proved encouraging. There is a way to get rid of the red color: (63) . When a bright light is shone on the mechanophore, the broken bond is fixed on and the red color disappears. This "self-healing" may be a problem for engineers. They need to use the color-changer in big construction projects that will be (64) , in sunlight. And sunlight will make the mechanophore's warning system useless. Sottos and her fellow scientists still have (65) work to do before the color-changing molecules can be used outside the lab.

单选题Their parents once 1iVed under very {{U}}severe {{/U}}conditions．

单选题On the brink of matrimony, he fled to a desert island.

单选题The new theory was corroborated. A. confirmed B. bleached C. hurled D. refrained

单选题From the incident, they have learned that prompt decisions often lead to biaer regrets.A. urgenB. hastyC. immediateD. wise

单选题Internet Technology Influence on Information Industry Wild Bill Donovan would have loved the Internet. The American spymaster who built the Office of Strategic Services in the World War Ⅱ and later laid the roots for the CIA was fascinated with information. Donovan believed in using whatever tools came to hand in the "great game" of espionage—spying as a "profession". These days the Net, which has already remade such everyday pastimes as buying books and sending mail, is reshaping Donovan"s vocation as well. The latest revolution isn"t simply a matter of gentlemen reading other gentlemen"s e-mail. That kind of electronic spying has been going on for decades. In the past three or four years, the World Wide Web has given birth to a whole industry of point-and-click spying. The spooks call it "open-source intelligence", and as the Net grows, it is becoming increasingly influential. In 1995 the CIA held a contest to see who could compile the most data about Burundi. The winner, by a large margin, was a tiny Virginia company called Open Source Solutions, whose clear advantage was its mastery of the electronic world. Among the firms making the biggest splash in this new world is Straitford, Inc., a private intelligence-analysis firm based in Austin, Texas. Straitford makes money by selling the results of spying (covering nations from Chile to Russia) to corporations like energy-services firm McDermott International. Many of its predictions are available online at www.straitford.com. Straitford president George Friedman says he sees the online world as a kind of mutually reinforcing tool for both information collection and distribution, a spymaster"s dream. Last week his firm was busy vacuuming up data bits from the far corners of the world and predicting a crisis in Ukraine. "As soon as that report runs, we"ll suddenly get 500 new Internet signups from Ukraine," says Friedman, a former political science professor. "And we"ll hear back from some of them." Open-source spying does have its risks, of course, since it can be difficult to tell good information from bad. That"s where Straitford earns its keep. Friedman relies on a lean staff of 20 in Austin. Several of his staff members have military-intelligence backgrounds. He sees the firm"s outsider status as the key to its success. Straitford"s briefs don"t sound like the usual Washington back-and-forthing, whereby agencies avoid dramatic declarations on the chance they might be wrong. Straitford, says Friedman, takes pride in its independent voice.

单选题A peculiarly pointed chin is his most memorable facial characteristic .

单选题{{U}}Persistent{{/U}} attempts to interview Garbo were fruitless.

单选题The great changes of the city astonished every visitor to that city.

单选题{{B}}第三篇{{/B}} {{B}}Geography and Movement{{/B}} To understand how astrology works, we should first take a quick look at the sky. Although the stars are at enormous distances, they do indeed give the impression of being affixed to the inner surface of a great hollow sphere surrounding the earth. Ancient people, in fact, literally believed in the existence of such a celestial sphere. As the earth spins on its axis, the celestial sphere appears to turn about us each day, pivoting at points on a line with the earth’s axis of rotation. This daily turning of the sphere carries the stars around the sky, causing most of them to rise and set, but they, and constellations they define, maintains fixed patterns on the sphere, just as the continent of Australian maintains its shape on a spinning globe of the earth. Thus the stars were called fixed stars. The motion of the sun along the ecliptic is, of course, merely a reflection of the revolution of the earth around the sun, but the ancients believed the earth was fixed and the sun had and independent motion of its own, eastward among the stars. The glare of sunlight hides the stars in daytime, but the ancients were aware that the stars were up there even at night, and the slow eastward motion of the sun around the sky, at the rate of about thirty degrees each month, caused different stars to be visible at night at different times of the year. The moon, revolving around the earth each month, also has an independent motion in the sky. The moon, however, changes it position relatively rapidly. Although it appears to rise and set each day, as does nearly everything else in the sky, we can see the moon changing position during as short an interval as an hour or so. The moon’s path around the earth lies nearly in the same plane as the earth’s path around the sun, so the moon is never seen very far from the ecliptic in the sky. There are five other objects visible to the naked eye that also appear to move in respect to the fixed background of stars on the celestial sphere. These are the planets Mercury, Venus, Mars, Jupiter, and the Saturn. All of them revolve around the sun in nearly the same plane as the earth does, so they, like the moon, always appear near the ecliptic. Because we see the planets from the moving earth, however, they behave in a complicated way, with their apparent motions on the celestial sphere reflecting both their own independent motions around the sun and our motion as well.

单选题The room was Ufurnished/U with the simplest essentials, a bed, a.chair, and a table.