单选题下面的短文后列出了7个句子，请根据短文的内容对每个句子做出判断：如果该句提供的是正确信息，请选择A；如果该句提供的是错误信息，请选择B；如果该句的信息文中没有提及，请选择C。 When We Are Asleep Everyone dreams, but some people never recall their dreams, or do so very rarely. Other people always wake up with vivid recollections (记忆) of their dreams, though they forget them very quickly. In an average night of eight hours' sleep, an average adult will dream for around one hundred minutes, probably having three to five dreams, each lasting from ten to thirty minutes. Scientists can detect when someone is having a dream by using an instrument which measures the electrical waves in the brain. During dreaming, these waves move more quickly. Breathing and pulse rate also increase, and there are rapid eye movements under the lids, just as though the dreamed were really looking at moving objects. These signs of dreaming have been detected in all mammals (哺乳动物) studied, including dogs, monkeys, cats, and elephants, and also some birds and reptiles (爬行动物). This period of sleep is called the" D" state for around 50% of their sleep; the period reduces to around 25% by the age of 10. Dreams take the form of stories, but they. may be strange and with incidents not connected, which make little sense. Dreams are seldom without people in them and they are usually about people we know. One estimate says that two-thirds of the" cast" of our dream dramas are friends and relations. Vision seems an essential part of dreams, except for people blind from birth. Sound and touch are senses also often aroused, but smell and taste are not frequently involved. In" normal" dreams, the dreamer may be taking part, or be only an observer. But he or she cannot control what happens in the dream. However, the dreamer does have control over one type of dream. This type of dream is called a "lucid"(清醒的) dream. Not everyone is a lucid dreamer. Some people are occasional lucid dreamers. Others can dream lucidly more or less all the time. In a lucid dream, the dreamer knows that he is dreaming.

单选题Houses in 18th Century North America Seventeenth-century houses in colonial North America were simple structures that were primarily functional, carrying over traditional designs that went back to the Middle Ages. During the first half of the eighteenth century, however, houses began to show a new elegance. As wealth increased, more and more colonists built fine houses. Since architecture was not yet a specialized profession in the colonies, the design of buildings was left to carpenters who undertook to interpret architectural manuals imported from England. There are an astonishing number of these handbooks for builders in colonial libraries, and the houses erected during the eighteenth century show their influence. Most domestic architecture of the first three-quarters of the eighteenth century displayed a wide range of taste and freedom of application of the rules laid down in these books. Increasing wealth throughout the colonies resulted in houses of improved design, whether the material was wood, stone or brick. New England still favored wood, though brick houses became common in Boston and other towns, where the danger of fire forced people to use more durable material. A few houses in New England were built of stone, but only in Pennsylvania and its neighboring areas was stone widely used in dwellings. An increased use of bricks is noticeable in Virginia and Maryland, but wood remained the most popular material even in houses built by wealthy landowners. In the Carolinas, even in the crowded town of Charleston, wooden houses were much more common than brick houses. Eighteenth-century houses showed great interior improvements over their predecessors. Windows were made larger and shutters (百叶窗) removed. Large, clear panes (玻璃窗) replaced the gray glass of the seventeenth century. Doorways were larger and more decorative. Fireplaces became decorative features of rooms. Walls were sometimes elaborately decorated. White paint began to take the place of blue, yellow, green and gray colors, which had been popular for walls in the earlier years. After about 1730, advertisements for wallpaper styles in scenic patterns began to appear in colonial newspapers.

单选题Moderate Earthquake Strikes England A moderate earthquake struck parts of southeast England on 28 April 200?, toppling chimneys from houses and rousing residents from their beds. Several thousand people were left without power in Kent County. One woman suffered minor head and neck injuries. "It felt as if the whole house was being slid across like a fun-fair ride," said the woman. The British Geological Survey said the 4.3-magnitude quake struck at 8.19 a. m. and was centered under the English Channel, about 8.5 miles south of Dover and near the entrance to the Channel Tunnel. Witnesses said cracks appeared in walls and chimneys collapsed across the county. Residents said the tremor had lasted for about 10 to 15 seconds. "I was lying in bed and it felt as if someone had just got up from bed next to me," said Hedrick van Eck, 27, of Canterbury about 60 miles southeast of London. "I then heard the sound of cracking, and it was getting heavier and heavier. It felt as if someone was at the end of my bed hopping up and down. " There are thousands of moderate quakes on this scale around the world each year, but they are rare in Britain. The April 28 quake was the strongest in Britain since 2002 when a 4.8-magnitude quake struck the central England city of Birmingham. The country"s strongest earthquake took place in the North Sea in 1931, measuring 6.1 on the Richter scale. British Geological Survey scientist Roger Musson said the quake took place on 28 April in an area that had seen several of the biggest earthquakes ever to strike Britain, including one in 1580 that caused damage in London and was felt in France. Musson predicted that it was only a matter of time before another earthquake struck this part of England. However, people should not be scared too much by this prediction, Musson aid, as the modern earthquake warning system of Britain should be able to detect a forthcoming quake and announce it several hours before it takes place. This would allow time for people to evacuate and reduce damage to the minimum.

单选题It"s prudent to start any exercise program gradually at first.

单选题Monarch without a Kingdom This November, a hundred million butterflies will drop from the sky over Mexico, like autumn leaves. But for how long? Genetically modified maize (玉米) could mean extinction for this beautiful butterfly, Rafael Ruiz reports. Although its body is about 3cm long and it only weighs 1 gin, the Monarch butterfly manages to travel 5,000km each year. It seems to be so fragile, but its long journeys are proof of its amazing ability to survive. This autumn, the Monarch butterfly will once more set out on its journey from the US. It will keep going until it reaches Mexico. It travels these huge distances to escape the cold weather in the north. In November, millions of Monarchs fall like bright, golden rain onto the forests in the mountains of central Mexico. In the silence of these mountains you can hear a strange flapping (拍动) of wings, as the Monarchs arrive at their destination. In the mountains, which reach a height of 3,000 metres, the butterflies are safe. Before reaching their journey"s end they have faced strong winds, rain and snowstorms and they do not all manage to reach their destination. When the winters are really bad, perhaps 70 percent of them will not survive. Their long journey to Mexico is thought to be one of the most amazing events in the whole of the American continent. When they get there they will stay until the beginning of April, when their internal calendar tells them that it is time to go back. The long journey, with all its dangers, begins again. These delicate creatures now face danger of another kind—from scientific progress. In the US, millions of farms grow genetically modified maize which is pure poison for the butterfly. Laboratory experiments have shown that half of the butterflies which feed on the leaves of genetically modified maize die within 48 hours. Not all experts agree that this variety of maize is responsible for the threat to the Monarchs. In spite of these doubts, the European Union has refused to approve new crops of genetically modified maize until further investigations have been carried out. Greenpeace is campaigning against genetically modified products (in Spain, there are already 20,000 hectares of modified maize). The environmental organization recently published a list of 100 species of butterfly in Europe alone which are threatened with extinction.

单选题 阅读下面的短文，文中有15处空白，每处空白给出了4个选项，请根据短文的内容从4个选项中选择1个最佳答案。 Highways in the US The United States is well-known for its network of major highways designed to help a driver get from one place to another in the shortest possible time.{{U}} (51) {{/U}}these wide modern roads are generally smooth and well maintained, with{{U}} (52) {{/U}}sharp curves and many straight sections, a direct route is not always the most{{U}} (53) {{/U}}one. Large highways often pass{{U}} (54) {{/U}} scenic areas and interesting small towns. Furthermore, these highways generally{{U}} (55) {{/U}}large urban centers which means that they become crowded with{{U}} (56) {{/U}}traffic during rush hours, when the "fast, direct" way becomes a very slow route. However, there is{{U}} (57) {{/U}}always an-other route to take if you are not in a hurry. Not far from the{{U}} (58) {{/U}}new "superhighways", there are often older,{{U}} (59) {{/U}}heavily traveled roads which go though the countryside.{{U}} (60) {{/U}} of these are good two lane roads; others are uneven roads{{U}} (61) {{/U}}through the country. These secondary routes may go up steep slopes along hilly{{U}} (62) {{/U}}or down frightening hillsides to towns{{U}} (63) {{/U}}in deep valleys. Though these are less direct routes, longer and slower, they generally go to places{{U}} (64) {{/U}}the air is clean and the scenery is beautiful, and the driver may have a chance to get a fresh, clean{{U}} (65) {{/U}}of the world.

单选题I can no longer {{U}}tolerate{{/U}} his actions.

单选题Dumped waste might {{U}}contaminate{{/U}} water supplies. A. destroy B. decrease C. pollute D. Delay

单选题Eleanor Roosevelt urged legislation to assist the poor and oppressed.

单选题By describing a typical situation of a lost driver on the road, the author intends to

单选题Batteries Built by Viruses What do chicken pox, the common cold, the flu, and AIDS have in common? They're all disease caused by viruses, tiny microorganisms that can pass from person to person. It's no wonder that when most people think about viruses, finding ways to steer clear of viruses is what's on people's minds. Not everyone runs from the tiny disease carders, though. In Cambridge, Massachusetts, scientists have discovered that some viruses can be helpful in an unusual way. They are putting viruses to work, teaching them to build some of the world's smallest rechargeable batteries. Viruses and batteries may seem like an unusual pair, but they're not so strange for engineer Angela Belcher, who first came up with the idea. At the Massachusetts Institute of Technology (MIT) in Cambridge, she and her collaborators bring together different areas of science in new ways. In the case of the virus-built batteries, the scientists combine what they know about biology, technology and production techniques. Belcher's team includes Paula Hammond, who helps put together the tiny batteries, and Yet-Ming Chiang, an expert on how to store energy in the form of a battery. "We're working on things we traditionally don't associate with nature." says Hammond. Many batteries are already pretty small. You can hold A, C and D batteries in your hand. The coin-like batteries that power watches are often smaller than a penny. However, every year, new electronic devices like personal music players or cell phones get smaller than the year before. As these devices shrink, ordinary batteries won't be small enough to fit inside. The ideal battery will store a lot of energy in a small package. Right now, Belcher's model battery, a metallic disk completely built by viruses, looks like a regular watch battery. But inside, its components are very small, so tiny you can only see them with a powerful microscope. How small are these battery parts? To get some idea of the size, pluck one hair from your head. Place your hair on a piece of white paper and try to see how wide your hair is pretty thin, right? Although the width of each person's hair is a bit different, you could probably fit about lots of these virus-built battery parts, side to side, across one hair. These micro-batteries may change the way we look at viruses.

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。 　　　　　　　　　　　　　　　　　　　{{B}}Sharks Perform a Service for Earth's Waters{{/B}} It is hard to get people to think of sharks as anything but a deadly enemy. They are thought to {{U}} (51) {{/U}} people frequently. Although these fish perform a valuable {{U}}(52) {{/U}} for earth's waters and for human beings. Yet business and sport fishing are threatening their {{U}}(53) {{/U}}. As a result, some sharks are at risk of disappearing from Earth. Warm weather may influence both fish and shark {{U}}(54) {{/U}}. Many fish swim near coastal areas because of their {{U}}(55) {{/U}} waters. Experts say sharks may follow the fish into the same areas, {{U}} (56) {{/U}} people also swim. In fact,most sharks do not purposely charge at or bite humans. They are thought to mistake a person {{U}}(57) {{/U}} a sea animal,such as a seal(海豹)or sea lion. That is why people should not swim in the ocean when the sun goes down or comes up. Those are the times when sharks are looking for {{U}}(58) {{/U}} Experts also say that bright colors and shiny jewelry(珠宝)may cause sharks to attack. A shark has an extremely good sense of {{U}}(59) {{/U}} ,with which it can find small amounts of substances in water, such as blood, body liquids and chemicals {{U}} (60) {{/U}} by animals. These powerful senses help sharks find their food. Sharks eat fish,any {{U}}(61) {{/U}} sharks,and plants that live in the ocean. Medical researchers want to learn more about the shark's body defense and immune (免疫的) {{U}} (62) {{/U}} against disease. Researchers know that sharks {{U}} (63) {{/U}} quickly from injuries. They study the shark in hopes of finding a way to fight human disease. Sharks are important for the world's oceans. They eat injured and diseased fish. Their {{U}} (64) {{/U}} activities mean that the numbers of other fish in ocean waters do not become too {{U}} (65) {{/U}}. This protects the plants and other forms of life that exist in the oceans.

单选题Easy Listening Students should be jealous. Not only do babies get to doze their days away, but they've also mastered the fine art of learning in their sleep. By the time babies are one year old, they can recognize a lot of sounds and even simple words. Marie Cheour at the University of Turku in Finland suspected that they might progress this fast because they learn language while they sleep as well as when they are awake. To test the theory, Cheour and their colleagues studied 45 newborn babies in the first days of their lives. They exposed all the infants to an hour of Finnish vowel sounds one that sounds like "oo"; another like "ee" and the third boundary vowel peculiar to Finnish and similar languages that sounds like something in between. EEG (脑电图) recording of the infants brains before and after the session showed that the newborns could not distinguish the sounds. Fifteen of the babies then went back with their mothers, where the rest were split into two sleep-study groups. One group was exposed throughout their night-time sleeping hours to the same three vowels, while the others listened to the other, easier-to-distinguish vowel sounds. When tested in the morning, and again in the evening, the babies who'd heard the tricky boundary vowels all night showed brainwave activity indicating that they could now recognize this sound. They could identify the sound even when its pitch was changed, while none of the other babies could pick up the boundary vowel at all. Cheour doesn't know how babies accomplish this nighttime learning, but she suspects that the special ability might indicate that unlike adults, babies don't "turn oft" their cerebral cortex (大脑皮层) while they sleep: The skill probably fades in the course of the first years of life, she adds so forget the idea that you can pick up the tricky French vowels as an adult just by slipping a language tape under your pillow. But while it may not help grown-ups, Cheour is hoping to use the sleeping hours to give remedial help to babies who are genetically at risk of language disorders.

单选题China to Help Europe Develop GPS Rival China is to contribute to a new global satellite navigation system being developed by European nations. The Galileo satellite system will 31 a more accurate civilian alternative to the Global Positioning System (GPS), operated by the US military. China will provide 230M Euros in funding and will 32 with technical, manufacturing and market development. A new center that will coordinate co-operation will be set 33 at Beijing University. China has a substantial satellite launch industry and could potentially help 34 the Galileo satellites. The US has claimed that Galileo could interfere with the US with 35 to downgrade the GPS service during military conflicts. European officials say this is unfounded (无根据的) and counter that US opposition is caused by the commercial challenge Galileo would present to GPS. Galileo will be 36 to within a meter, while the civilian GPS service is accurate to around 10 meters. The Galileo satellite constellation (卫星集群) will consist of 27 operational and three reserve satellites 37 the Earth at an altitude of 23,600 kin. The satellites will be strung along three medium-Earth orbits at 56 degrees inclination (倾斜) 38 the equator (赤道) and will provide global coverage. The system should be 39 by 2008 and the entire project is expected to cost around 3.2 billion Euros The European Commission has said Galileo wilt 40 be used for transportation technology, scientific research, land management and disaster monitoring. Galileo will provide two 41 ; a standard civilian one and an encrypted (把……编码), wide-band signal called the Public Regulated Service (PRS). This second signal is 42 to endure localized jamming and will be used by police and military services in Europe. The first Galileo satellite is 43 to launch late in 2004. Clocks on board the satellites will be synchronized (同步) through 20 ground sensors (传感器) stations, two command centers and 15 uplink (上传) stations. Receivers on the ground will use time signals from the satellites to precisely calculate their 44 . A "search and rescue" function will also let distress signals be 45 through the constellation of satellites.

单选题 A Health Profile A health profile is a portrait of all of the factors that influence your health. To draw your health profile, you will {{U}} {{U}} 1 {{/U}} {{/U}}what diseases run in your family, what health hazards you may be exposed to {{U}} {{U}} 2 {{/U}} {{/U}}work, how your daily {{U}} {{U}} 3 {{/U}} {{/U}}compares to the recommended standards, how much time per week you {{U}} {{U}} 4 {{/U}} {{/U}}exercising and what type of exercise you engage {{U}} {{U}} 5 {{/U}} {{/U}}, how stressful your work and family environments are, what kinds of illnesses you get regularly, and {{U}} {{U}} 6 {{/U}} {{/U}}or not you have any one of a number of addictions. {{U}} {{U}} 7 {{/U}} {{/U}}this portrait, your should have a checkup to determine how your blood, heart, and lungs are functioning. This checkup will serve {{U}} {{U}} 8 {{/U}} {{/U}}a baseline, to which you can then compare later tests. {{U}} {{U}} 9 {{/U}} {{/U}}this profile is thoroughly drawn, you can begin to think about setting health priorities based {{U}} {{U}} 10 {{/U}} {{/U}}your particular portrait. For example, if you drink two martinis every evening, have a high-stress {{U}} {{U}} 11 {{/U}} {{/U}}, are overweight, smoke a pack of cigarettes a day, and use marijuana occasionally on weekends, you should quit smoking first, followed {{U}} {{U}} 12 {{/U}} {{/U}}losing the excess weight, reducing the stress of your job, giving up your marijuana habit, and then finally giving some {{U}} {{U}} 13 {{/U}} {{/U}}to those martinis if you want to prevent first cancer, and then heart disease. Even for the youthful working person who has never been sick a day in his life, who is {{U}} {{U}} 14 {{/U}} {{/U}}excellent health, a good look at all health habits and at work and home environments may suggest changes that will {{U}} {{U}} 15 {{/U}} {{/U}}him in the future.

单选题We need to extract the relevant financial data.

单选题Radioactive Wastes One of the major problems of nuclear energy is the inability of scientists to discover a safe way to dispose of the radioactive wastes which occur throughout the nuclear process. Many of these wastes remain dangerously active for tens of thousands of years, while others have a life span closer to a quarter of a million years. Various methods have been used to date, but all have revealed weaknesses, forcing scientists to continue their search. The nuclear process involves several stages, with the danger of radioactivity constantly present. Fuel for nuclear reactors comes from uranium ore (铀矿石), which, when mined, spontaneously produces radioactive substances as by-products. This characteristic of uranium ore went undetected for a long time, resulting in the deaths, due to cancer, of hundreds of uranium miners. The United States attempted to bury much of its radioactive waste material in containers made of steel covered in concrete and capable of holding a million gallons. For a long time it was believed that the nuclear waste problem had been solved, until some of these tanks leaked, allowing the radioactive wastes to seep into the environment. Canada presently stores its nuclear waste in underwater tanks, with the long-term effects largely unknown. However, plans are under consideration for above-ground storage of spent fuel from reactors. These plans include the building of three vast concrete containers, which would be two stories high and approximately the length and width of two football fields. Other suggestions include enclosing the waste in glass blocks and storing them in underground caverns, or placing hot containers in the Antarctic region, where they would melt the ice, thereby sinking down about a mile. This idea has since been abandoned because of the possible adverse effect on the ice sheets.

单选题Hurricane Katrina A hurricane is a fiercely powerful, rotating form of tropical storm that can be 124 to 1,240 miles in diameter. The term hurricane is derived from Hurican, the name of a native American storm god. Hurricanes are typical of a calm central region of low pressure between 12 to 60 miles in diameter, known as the eye. They occur in tropical regions. Over its lifetime, one of these storms can release as much energy as 10,000 nuclear bombs. The seed for hurricane formation is a cluster of thunderstorms over warm tropical waters. Hurricanes can only form and be fed when the sea-surface temperature exceeds 27℃ and the surrounding atmosphere is calm. These requirements are met between June and November in the northern hemisphere. Under these conditions, large quantities of water evaporate and condense into clouds and rain—releasing heat in the process. It is this heat energy, combined with the rotation of the Earth that drives a hurricane. When the warm column of air from the sea surface first begins to rise, it causes an area of low pressure. This in turn creates wind as air is drawn into the area. This spinning wind drags up more moisture-laden air from the sea surface in a process that swells the storm. Cold air falls back to the ocean surface through the eye and on the outside of the storm. Initially, when wind speeds reach 23 miles per hour, these mild, wet and grey weather systems are known as depressions. Hurricane Katrina formed in this way over the south- eastern Bahamas on 23 August 2005. Katrina has had a devastating impact on the Gulf Coast of the US, leaving a disaster zone of 90, 000 square miles in its wake—almost the size of the UK. Thousands have been killed or injured and more than half a million people have been displaced in a humanitarian crisis of a scale not seen in the US since the great depression. The cost of the damage may top $100 billion.

单选题New Brain Cells Love to Learn Wisdom in old age depends on a fresh supply of new brain cells, a study in mice suggests. When mature mice learn a new task, their newly generated brain cells are three times more active than their old ones, the researchers found. The findings add to a growing body of evidence that the adult brain needs a steady addition of new cells to maintain its mental faculties. Paul Frankland at the Hospital for Sick Children in Toronto, Ontario, Canada, and colleagues injected a group of mice with a chemical agent that stains only those cells born in the animals' brains at the time of injection. One week later, the team taught some of the mice how to navigate through a maze (迷宫), before sacrificing them to analyse the cells in a region of the brain called the hippocampus(海马体),which is key to learning and memory. In stages, the rest of the mice also underwent this paired process of learning and hippocampal examination at increasing time intervals from the initial injection. Frankland's team analysed the mice's stained hippocampal cells for key proteins—evidence that the cells were active and forming the new neural connections vital for learning. The team found that the stained cells had undergone significantly more activity in the mice that had learned the maze soon after the injection-when the stained cells were newly generated. For example, those that had learned the maze six weeks after the injection had three times as much "activity" in their stained cells as those mice that learned the maze eight weeks after injection, when the stained cells were fully mature. Cells examined at less than six weeks' old at the time of learning did not show as much activity as at six weeks, however. According to Frankland, this suggests that when neurons reach six weeks of age they are specifically recruited to form the brain networks that support new memories. "The results strengthen the link between new cells in the adult brain and learning-and shows more convincingly that they have a functional role," Frankland says. He believes the study is the first to provide positive evidence that newly generated brain cells are more active than old ones.

单选题For many years my uncle ran a very Usuccessful/U engineering business.