单选题It can be learnt from what Radel says that

单选题 Continue to Protect or Destroy Ecosystem Biosphere Ⅱ was a spectacular failure. The gleaming glass-and-concrete habitat sprawling across the desert in Oracle, Arizona, was supposed to support eight human "biospherians" for two years. But the seal has to be broken before the experiment ended in 1993. Oxygen had fallen to levels normally seen at an elevation of 17,500 feet. Nitrous oxide had risen to the point where it threatened to cause brain damage. The fresh water supply became contaminated, and vines smothered (厚厚地覆盖) food plants. Insect pollinators (传授花粉的生物) and many other species became extinct. By the end, Biosphere Ⅱ was overrun with swarms of ants and cockroaches. Scientists who gathered recently to review the Biosphere Ⅱ experiment reached a disturbing conclusion: "No one yet knows how to engineer systems that provide humans with the life-supporting services that natural ecosystems produce for free." The problem is that these ecosystems are undergoing wrenching changes. Water and air quality, while improving in some regions, are deteriorating in many others. Carbon dioxide levels in the atmosphere are climbing. The world's population could reach 10 billion by 2050. And famed Harvard biologist Edward O. Wilson says the current rate of species losses puts us "in the midst of one of the great extinction spasms (突然进发) of geological history." All of which makes many ecologists wonder whether humans too will soon become extinct. It's an incredibly important but incredibly difficult question. If we continue on this course, we're heading for a world in which we will have to engineer services we've always received for free from nature. That's why the failure of Biosphere Ⅱ was so disturbing: it proves that we don't yet know how to do that. The Biosphere Ⅱ experience demonstrated that maintaining human life is a tricky proposition-especially if we can no longer rely on the services provided by natural ecosystems. If we are currently living through a mass extinction, as Wilson believes, we should consider the past. In the great Permian extinction 245 million years age, 96 percent of species perished. Eventually, the Earth was repopulated with a rich collection of new species, but it took 100 million years. "That should give pause to anyone who believes that what Homo sapiens (现代人) destroys, nature will redeem," Wilson says. "Maybe so, but not within any length of time that has meaning for contemporary humanity."

单选题The nursery is bright and {{U}}cheerful{{/U}}.

单选题Shopping for Clothes Shopping for clothes is not the same experience for a man as it is for a woman. A man goes shopping because he needs something. His purpose is settled and decided in 1 . He knows what he wants, and his 2 is to find it and buy it. All men simply walk into a shop and ask the assistant for what they want. If the shop has it in stock, the deal can be and often is completed in less than five minutes, with hardly any chat and to everyone"s 3 . For a man, slight problems may begin when the shop does not have what he wants. In that 4 the salesman tries to sell the customer something else—he offers the nearest to the article required. Good salesman brings out such a substitute with 5 : "know this jacket is not the style you want, sir, but would you like to try it for size. It 6 to be the colour you mentioned." Few men have 7 with this treatment, and the usual response is: "This is the right colour and may be the right size, but I should be 8 my time and yours by trying it on." For a woman, buying clothes is always done in the 9 way. Her shopping is not often 10 on need. She has never fully decided what she wants, and she is only "having a look round". She is always open to persuasion, willing to try 11 any number of things. Uppermost in her mind is the thought of finding something that 12 thinks suits her. Most women have an excellent sense of value and are always on the look-out for the unexpected 13 . Faced with a roomful of dresses, a woman may easily spend an hour going from one rail to another 14 selecting the dresses she wants to try on. It is a tiresome process, but apparently a(n) 15 one. Most dress shops provide chairs for the waiting husbands.

单选题Women's minds work differently from men's. At least, that is what most men are convinced of. Psychologists view the subject either as a matter of frustration or a joke. Now the biologists have moved into this minefield, and some of them have found that there are real differences between the brains of men and women. But being different, they point out hurriedly, is not the same as being better or worse. There is, however, a definite structural variation between the male and female brain. The difference is in a part of the brain that is used in the most complex intellectual processes—the link between the two halves of the brain. The two halves are linked by a trunk line of between 200 and 300 million nerves, the corpus callosum. Scientists have found quite recently that the corpus callosum in women is always larger and probably richer in nerve fibres than it is in men. This is the first time that a structural difference has been found between the brains of women and men and it must have some significance. The question is "What?", and, if this difference exists, are there others? Research shows that present-day women think differently and behave differently from men. Are some of these differences biological and inborn, a result of evolution? We tend to think that is the influence of society that produces these differences. But could we be wrong? Research showed that these two halves of the brain had different functions, and that the corpus callosum enabled them to work together. For most people, the left half is used for word-handling, analytical and logical activities ; the right half works on pictures, patterns and forms. We need both halves working together. And the better the connections, the more harmoniously the two halves work. And, according to research findings, women have the better connections. But it isn't all that easy to explain the actual differences between skills of men and women on this basis. In schools throughout the world girls tend to be better than boys at "language subjects" and boys better at maths and physics. If these differences correspond with the differences in the hemispheric trunk line, there is an unalterable distinction between the sexes. We shan't know for a while, partly because we don't know of any precise relationship between abilities in school subjects and the functioning of the two halves of the brain, and we cannot understand how the two halves interact via the corpus callosum. But this striking difference must have some effect and, because the difference is in the parts of the brain involved in intellect, we should be looking for differences in intellectual processing.

单选题The first generation of dot-corns burned through cash rapidly because they had to spend a lot of money building and running their businesses—marketing and advertising to get the word out, not to mention software, consultants, and programmers to run online systems and" analyze theresults. Thanks to Web 2.0, many of these costs have plummeted. Many of the basics are nowessentially free, which means a business built on the infrastructure laid down by the first two generations of Web companies can gain scale on a shoestring budget, all while giving away its products and services for free. Call it Web 2.5. The first generation dot-coms spent a huge sum of moneyA. marketing and advertising their products.B. training their employees.C. hiring consults and programmers.D. analyzing the data transmitted onto the we

单选题Credit Card Only Works When Spoken To A credit card that will not work unless it hears its owner's voice could become an important weapon in the fight against fraud (欺骗). The card requires users to give a spoken password that it recognizes using a built-in voice-recognition chip. The idea is to prevent thieves using a stolen card or fraudsters using someone else's credit card details to buy goods online. A model built by engineers at Beepcard in Santa Monica, California, represents the first attempt to pack a microphone, a loudspeaker, a battery and a voice-recognition chip into a standard-sized credit card. They are not quite there yet: the card is the length and width of an ordinary credit card, but it is still about three times as thick. The company now plans to make it thinner. The voice card is based on an earlier Beepcard technology designed to prevent fraud in online transactions. This earlier card has no microphone, but has a built-in loudspeaker that it uses to "squawk" (发出叫声) a voice ID signal via a computer's microphone to an online server. By verifying (证实) that the signal matches the card details, the server can establish that the user is not simply keying in a credit card number but actually has the card to hand. The ID code changes each time the card is used in a pre-ordered sequence that only the server knows. This prevents fraudsters recording the beeps, noting the card details and then playing back the audible ID when they key in the details later. But this earlier technology cannot prevent fraudulent use of stolen cards. The new one can. The new voice card also identifies itself by its ID squawk, but it will not do this until it has verified the legitimate (合法的) user's spoken password. Thieves will be unable to use the card because even if they knew the password they would have to be able to copy the owner's voice with a high degree of accuracy. The challenge for Beepcard has been to develop voice-recognition and audio circuitry that can be powered by a mini battery embedded (潜入的) in a credit card. To maximize battery life, the electronics are only switched on when the card is being used. Pressing a button on the card's surface prompts it to utter "Say your password" in female voice. If the voice-recognition software proves that the password is authentic (真实的), it sends its ID squawk which the server then identifies, allowing the transaction to proceed.

单选题 Invisibility Ring Scientists can't yet make an invisibility cloak(斗篷) like the one that Harry Potter uses. But, for the first time, they've constructed a simple cloaking device that makes itself and something placed inside it invisible to microwaves. When a person "sees" an object, his or her eye senses many different waves of visible light as they bounce off the object. The eye and brain then work together to organize these sensations and reconstruct the object's original shape. So, to make an object invisible, scientists have to keep waves from bouncing off it. And they have to make sure the object casts no shadow. Otherwise, the absence of reflected light on one side would give the object away. Invisibility isn't possible yet with waves of light that the human eye can see. But it is now possible with microwaves(微波). Like visible light, microwaves are a form of radiant energy. They are part of the electromagnetic spectrum(电磁波频谱), which also includes radio waves, infrared light, ultraviolet rays, X rays, and gamma rays. The wavelengths of microwaves are shorter than those of radio waves but longer than those of visible light. The scientists' new "invisibility device" is the size of a drink coaster and shaped like a ring. The ring is made of a special material with unusual ability. When microwaves strike the ring, very few bounce off it. Instead, they pass through the ring, which bends the waves all the way around until they reach the opposite side. The waves then return to their original paths. To a detector set up to receive microwaves on the other side of the ring, it looks as if the waves never changed their paths as if there were no object in the way! So, the ring is effectively invisible. When the researchers put a small copper loop inside the ring, it, too, is nearly invisible. However, the cloaking device and anything inside it do cast a pale shadow. And the device works only for microwaves, not for visible light or any kind of electromagnetic radiation. So, Harry Potter's invisibility cloak doesn't have any real competition yet.

单选题Her death was a grief to him and I doubt if he ever recovered afterwards.A. got byB. got throughC. got onD. got over

单选题The project was completed on time because the cooperation between the two compames.A. cooperationB. connectionC. combinationD. agreement

单选题Human beings cannot {{U}}exist{{/U}} without air.

单选题After entering the room, he removed his overcoat.A. movedB. put offC. took offD. threw

单选题A Great Quake Coming? Everyone who lives in San Francisco knows that earthquakes are common in the bay area and they can be devastating. In 1906, for example, a major quake destroyed about 28,000 buildings and killed hundreds, perhaps thousands of people. Residents now wonder when the next "Big One" will strike. It's bound to happen someday. At least seven active fault (断层) lines run through the San Francisco area. Faults are places where pieces of Earth's crust (地壳) slide past each other. When these pieces slip, the ground shakes. To prepare for that day, scientists are using new techniques to reanalyze the 1906 earthquake and predict how bad the damage might be when the next one happens. One new finding about the 1906 earthquake is that the San Andreas fault split apart faster than scientists had assumed at the time. During small earthquakes, faults rupture. (断裂) at about 2.7 kilometers per second. During bigger quakes, however, ruptures can happen at rates faster than 3.5 kilometers per second. At such high speeds, massive amounts of pressure build up, generating underground waves that can cause more damage than the quake itself. Lucky for San Francisco, these pressure pulses travel away from the city during the 1906 event. As bad as the damage was, it could have been far worse. Looking ahead, scientists are trying to predict when the next major quake will occur. Records show that earthquakes were common before 1906. Since then, the earthquake has been relatively quiet. Patterns in the data, however, suggest that the probability of a major earthquake striking the Bay Area before 2032 is at least 62 percent. New buildings in San Francisco are quite safe in case of future quakes. Still, more than 84 percent of the city's buildings are old and weak. Analyses suggest that another massive earthquake would cause extensive damage. People who live there tend to feel safe because San Francisco has remained pretty quiet for a while. According to the new research, however, it's not a matter of "if the Big One will hit". It's just a matter of when.

单选题{{B}}第二篇{{/B}} {{B}}Can Buildings Be Designed to Resist Terrorist Attack?{{/B}} In the aftermath of the terrorist attack on the World Trade Center, structural engineers are trying hard to solve a question that a month ago would have been completely unthinkable: Can building be designed to withstand catastrophic blasts inflicted by terrorists? Ten days after the terrorist attacks on the twin towers, structural engineers from the University at Buffalo and the Multidisciplinary Center for Earthquake Engineering Research (MCEER) headquartered at UB traveled to ground zero as part of a project funded by file National Science Foundation, visiting the site as part of an MCEER reconnaissance visit. They spent two days beginning the task of formulating ideas about how to design such structures and to search for clues on how to do so in buildings that were damaged, but still are standing. "Our objective in visiting ground zero was to go and look at the buildings surrounding the World Trade Center, those buildings that are still standing, but that sustained damage" said M. Bruneau. Ph. D. "Our immediate hope is that we can develop a better understanding as to why those buildings remain standing. While our long-term goal is to see whether earthquake engineering technologies can be married to existing technologies to achieve enhanced performance of buildings in the event of terrorist attacks," he added. Photographs taken by the investigators demonstrate in startling detail the monumental damage inflicted on the World Trade Center towers and buildings in the vicinity. One building a block away from the rowers remains standihg, but was badly damaged. "This building is many meters away from the World Trade Center and yet we see a column there that used to be part of that building." explained A. Whittaker. Ph. D. "The column became a missile that shot across the road. through the window and through the floor." The visit to the area also revealed some surprises, according to the engineers. For example, the floor flaming system in one of the adjacent buildings was quite rugged, allowing floors that were pierced by tons of fairing debris to remain intact. "Highly redundant ductile framing systems may provide a simple, but robust strategy for blast resistance," he added. Other strategies may include providing alternate paths for gravity loads in the event that a load-bearing column fails. "We also need a better understanding of the mechanism of collapse." said A. Whitaker. "We need to find out what causes a building to collapse and how you can predict it." A. Reinhorn, Ph. D. noted that "earthquake shaking has led to the collapse of many buildings in the past. It induces dynamic response and extremely high stresses and deformations in structural components. Solutions developed for earthquake resistant design may be directly applicable to blast engineering and terrorist. Part of our mission now at UB is to transfer these solutions and to develop new ones where none exist at present." aftermath n. 后果，结果 in the vicinity 附近 debris n. 碎片 reconnaissance n. 勘察；侦察 ductile adj. 可伸展的，易变形的

单选题Located in Washington, D.C., the Library of Congress contains an imposing {{U}}array{{/U}} of books on every conceivable subject.

单选题They Say Ireland"s the Best Ireland is the best place in the world to live in for 2005, according to a life quality ranking that appeared in Britain"s Economist magazine last week. The ambitious attempt to compare happiness levels around the world is based on the principle that wealth is not the only measure of human satisfaction and well-being. The index of 111 countries uses data on incomes, health, unemployment, climate, political stability, job security, gender equality as well as what the magazine calls "freedom, family and community life". Despite the bad weather, troubled health service, traffic congestion (拥挤), gender inequality and the high cost of living, Ireland scored an impressive 8.33 points out of 10. That put it well ahead of second-place Switzerland, which managed 8.07. Zimbabwe troubled by political insecurity and hunger, is rated the gloomiest (最差的), picking up only 3.89 points. "Although rising incomes and increased individual choices are highly value," The report said, "some of the factors associated with modernization such as the breakdown (崩溃) in traditional institutions and family values in part take away from a positive impact." "Ireland wins because it successfully combines the most desirable elements of the new with the preservation of certain warm elements of the old, such as stable family and community life." The magazine admitted measuring quality of life is not a straightforward thing to do, and that its findings would have their critics. No. 2 on the list is Switzerland. The other nations in the top 10 are Norway, Luxembourg, Sweden, Australia, Iceland, Italy, Denmark and Spain. The UK is positioned at No. 29, a much lower position chiefly because of the social and family breakdown recorded in official statistics. The US, which has the second highest per capita GDP (人均国内生产总值) after Luxembourg, took the 13th place in the survey. China was in the lower half of the league at 60th.

单选题Changes in Museums Museums have changed. They are no longer places that one "should" visit; they are places to enjoy and learn. At a Science museum in Ontario, Canada, you can feel your hair stand on end as harmless electricity passes through your body. At the Metropolitan (大城市的) Museum of Art in New York City, you can look at the seventeenth century instruments while listening to their music. At New York"s American Museum of Natural History recently, you can help make a bone-by-bone reproduction of the museum"s dinosaur (恐龙), a beast that lived 200 million years ago. More and more museum directors are realizing that people learn best when they can somehow become part of what they are seeing. In many science museums, for example, there are no guided tours. The visitor is encouraged to touch, listen, operate, and experiment so as to discover scientific principles for himself. The purpose is not only to provide fun but also to help people feel at home in the world of science. The theory is that people who do not understand science will probably fear it, and those who fear science will not use it to best advantage. One cause of all these changes is the increase in wealth and leisure time. Another cause is the rising percentage of young people in the population. Many of these young people are college students or college graduates. Leon F. Twiggs, a young black professor of art once said, "They see things in a new and different way. They are not satisfied to stand and look at works of art; they want art they can participate (参加) in. "The same is true of science and history.

单选题Do you follow what I am saying?

单选题Longer Lives for Wild Elephants Most people think of zoos as safe places for animals, where struggles such as difficulty finding food and avoiding predators don't exist. Without such problems, animals in zoos should live to a ripe old age. But matter may not be true for the largest land animals on Earth. Scientists have known that elephants in zoos often suffer from poor health. They develop diseases, joint problems and behavior changes. Sometimes, they even become infertile or unable to have babies. To learn more about how captivity affects elephants, a team of international scientists compared the life spans of female elephants born in zoos with female elephants living outdoors in their native lands. Zoos keep detailed records of all the animals in their care, documenting factors such as birth dates, illnesses, weight and death. These records made it possible for the researchers to analyze 40 years of data on 800 African and Asian elephants in zoos across Europe. The scientists compared the life spans of the zoo born elephants with the life spans of thousands of female wild elephants in Africa and Asian elephants that work in logging camps, over approximately the same time period. The team found that female African elephants born in zoos lived an average of 16.9 years. Their wild counterparts who died of natural causes lived an average of 56 years--more than three times as long. Female Asian elephants followed a similar pattern. In zoos, they lived 18.9 years, while those in the logging camps lived 41.7 years. Scientists don't yet know why wild elephants seem to fare so much better than their zoo-raised counterparts. Georgia Mason, a biologist at the University of Guelph in Canada who led the study, thinks stress and obesity may be to blame. Zoo elephants don't get the same kind of exercise they would in the wild, and most are very fat. Elephant social lives are also much different in zoos than in the wild, where they live in large herds and family groups. Another finding from the study showed that Asian elephants born in zoos were more likely to die earlier than Asian elephants captured in the wild and brought to zoos. Mason suggests stress in the mothers in zoos might cause them to have babies that are less likely to survive. The study raises some questions about acquiring more elephants to keep in zoos. While some threatened and endangered species living in zoos reproduce successfully and maintain healthy populations, which doesn't appear to be the case with elephants." Currently, zoos alert consumers of elephants, not net producers," Mason says.

单选题Poor schooling was the Uroot/U of the unemployment problem.