单选题Walk along this corridor, and you will see the queen's private chamber.A. officeB. toiletC. bedroomD. living room

单选题It is possible to {{U}}approach{{/U}} the problem in a different way. A. handle B. raise C. pose D. experience

单选题Late-Night Drinking Coffee lovers beware. Having a quick "pick-me-up" cup of coffee late in the day will play havoc with your sleep. As well as being a stimulant, caffeine interrupts the flow of melatonin, the brain hormone that sends people into a sleep. Melatonin levels normally start to rise about two hours before bedtime. Levels then peak between 2 am and 4 am, before falling again. "It's the neurohormone that controls our sleep, and tells our body when to sleep and when to wake," says Maurice Ohayon of the Stanford Sleep Epiderniology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone. Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six volunteers slept less well after a cup of caffeinated coffee than after drinking the same amount of decal On average, subjects slept 336 minutes per night after drinking caffeinated coffee, compared with 415 minutes after decaf. They also took haft an hour to drop off--twice as long as usual -- and jigged around in bed twice as much. In the second phase of the experiment, the researchers woke the volunteers every three hours and asked them to give a urine sample. Shilo measured concentrations of a breakdown product of melatonin. The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers. In a paper accepted for publication in Sleep Medicine, the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production. Because it can take many hours to eliminate caffeine from the body, Ohayon recommends that coffee lovers switch to decaf after lunch.

单选题Lack of space Uforbids/U further treatment of the topic here.

单选题Unpopular Subjects? Is there a place in today's society for the study of useless subjects in our universities? Just over 100 years ago Fitzgerald argued in a well-written letter (1) Nature that "Universities must be allowed to study useless subjects— (2) they don't, who will?" He went on to use the (3) of Maxwell's electrodynamics (电动力学) as one case where a "useless subject" has been transformed to a useful subject. Nowadays this argument is again very much (4) in many universities. Indeed one suspects that it is one of those arguments that must be (5) anew (重新) by each generation. But now there is an added twist (歪曲)—subjects must not only be useful, they must also be (6) enough that students will flock (蜂拥) to do them, and even flock to pay to do them. As universities become commercial operations, the pressure to (7) subjects or departments that are less popular will become stronger and stronger. Perhaps this is most strongly (8) at the moment by physics. There has been much (9) in the press of universities that are closing down physics departments and incorporate them with mathematics or engineering departments. Many scientists think otherwise. They see physics as a (10) science, which must be kept alive if only to (11) a base for other sciences and engineering. It is of their great personal concern that physics teaching and research is under (12) in many universities. How can it be preserved in the rush towards commercial competition? A．major turnaround (转变) in student popularity may have to (13) until the industrial world discovers that it needs physicists and starts paying them well. Physics is now not only unpopular: it is also "hard". We can do more about the latter by (14) teaching in our schools and universities. We can also (15) cooperative arrangements to ensure that physicists keep their research and teaching up to date.

单选题The leading astronomers of the sixteenth and seventeenth centuries were fascinated by comets.

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。 Jetlag Most people who travel long distances complain of jetlag (喷气飞行时差反应). Jetlag makes business travelers less productive and more prone {{U}}(51) {{/U}} making mistakes. It is actually caused by {{U}}(52) {{/U}} of your "body clock" -a small cluster of brain cells that controls the timing of biological {{U}}(53) {{/U}}. The body clock is designed for a regular rhythm of daylight and darkness-ness, so that it is thrown out of balance when it {{U}}(54) {{/U}} daylight and darkness at the "wrong" times in a new time zone. The symptoms of jetlag often persist for days {{U}}(55) {{/U}} the internal body clock slowly adjusts to the new time zone. Now a new anti-jetlag system is {{U}}(56) {{/U}} that is based on proven tentative pioneering scientific research. Dr. Martin Moore Ede has {{U}}(57) {{/U}} a practical strategy to adjust the body clock much sooner to the new time zone {{U}}(58) {{/U}} controlled exposure to bright light. The time zone shift is easy to accomplish and eliminates most of the discomfort of jetlag. A successful time zone shift depends on knowing the exact times to either {{U}}(59) {{/U}} or avoid bright light. Exposure sure to light at the wrong time can actually make jetlag worse. The proper schedule {{U}}(60) {{/U}} light exposure depends a great deal on {{U}}(61) {{/U}} travel plans. Data on a specific flight itinerary (旅行路线) and the individual's sleep {{U}}(62) {{/U}} are used to produce a Trip Guide with instructions on exactly when to be exposed to bright light. When the Trip Guide calls {{U}}(63) {{/U}} bright light you should spend time outdoors if possible. If it is dark outside, or the weather is bad, {{U}}(64) {{/U}} you are on an aero plane, you can use a special light device to provide the necessary light {{U}}(65) {{/U}} for a range of activities such as reading, watching TV or working.

单选题Dolphins travel faster in water than any other animals.

单选题It is a marvel that he remained alive after dropping from the roof of a six-storied building.A. curiosityB. wonderC. wanderD. spectacle

单选题The use of the chemical may present a certain hazard to the laboratory workers.

单选题California Gives Green Light to Space Solar Power Energy beamed down from space is one step closer to reality, now that California has given the green light to an agreement that would see the Pacific Gas and Electric Company buy 200 megawatt(兆瓦)of power beamed down from solar-power satellites beginning in 2016. But some major challenges will have to be overcome if the technology is to be used widely. A start-up company called Solaren is designing the satellites, which it says will use radio waves to beam energy down to a receiving station on Earth. The attraction of collecting solar power in space is the almost uninterrupted sunshine available in eosynchronous(与地球同步的)orbit. Earth-based solar cells, by contrast, can only collect sun light during daytime and when skies are clear. But space-based solar power must grapple(努力克服)with the high cost per kilo-gram of launching things into space, says Richard Schwartz of Purdue University in West Lafayette, Indiana. "If you"re talking about it being economically viable or power of the Earth, it"s a tough go." he says. Cal Boer man, Solaren"s director of energy services, says the company designed its satellites with a view to keeping launch costs down. "We knew we had to come up with a different, revolutionary design," he says. A patent the company has won describes ways to reduce the system"s weight, including using inflatable mirrors to focus sunlight on solar cells, so a smaller number can collect the same amount of energy. But using minors introduces other challenges, including keeping the solar cells from overheating, says Schwartz. "You have to take care of heat dissipation(散发)because you"re now concentrating a lot of energy in one place," he says. According to the company"s patent, Solaren"s solar cells will be connected to radiators to help keep them cool. Though Boer man says the company believes it can make space-based solar power work, it is not expecting to crowd out other forms of renewable energy. Laws in California and other states require increasing use of renewable energy in coming years, he points out. "To meet those needs, we"re going to need all types of renewable energy sources," he says.

单选题Microelectronics Revolution The 1980s are likely to be considered as a more than somewhat interesting decade for the United Kingdom and indeed for other industrialized countries. The political, social and economic autonomic reflexes in operation for the greater part of this century will have to give way to the new as conditions change. Paramount amongst these changes is the advent of microelectronics with their ability to increase productivity and the end of cheap, easily manipulated sources of energy. Together these will undoubtedly change the pattern of industrialization and industrialized life in a radical manner not seen in the UK since the early 19th century. Most technological changes are somewhat less than fundamental. Many act on an individual process of industry and so their effects on the general economy can be boxed off. Others act on the demand side with new products, often for new markets. Microelectronics, though, are different. It is difficult to think of parts of the economy on which they will not have an impact; it is especially very difficult to think of the many new consumer products that will evolve. It is already being used, in productive processes through robotics, in production planning through cheap computers, as cheap and easy to maintain components, and through telecommunications, teletext systems and word processing to provide, transmit and store information. The resulting large increases in productivity will mean that increased levels of output will be produced using fewer resources of manpower, raw materials and energy. On the face of it this has to be a good thing, it opens vistas that were previously closed. The cost, however, is measured in terms of the resulting job losses, job changes and lack of new jobs. If we sit back and allow the market to work allocating wealth and jobs-in other words-continue as we are at present, either the technologies will not be introduced at all or there will be social confrontation on a massive scale. This new technology improves productivity at precisely the time world trade growth is declining, and this is likely to diminish even further given the responses to the shortage of energy sources. This will almost certainly mean that our ability to supply will outstrip (超过) our ability to demand, giving a classic high unemployment.

单选题阅读下面这篇短文，短文后列出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；如果该句的信息文章中没有提及，请选择C。 The temperature of the Sun is over 5,000 degrees Fahrenheit at the surface, but it rises to perhaps more than 16 million degrees at the center. The Sun is so much hotter than the Earth that matter can exist only as a gas, except at the core. In the core of the Sun, the pressures are so great against the gases that, despite the high temperature, there may be a small solid core. However, no one really knows, since the center of the Sun can never be directly observed. Solar astronomers do know that the Sun is divided into five layers or zones. Starting at the outside and going down into the Sun, the zones are the corona, chromosphere, photosphere, convection zones, and finally the core. The first three zones are regarded as the Sun' s atmosphere. But since the Sun has no solid surface, it is hard to tell where the atmosphere ends and the main body of the Sun begins. The Sun's outermost layer begins about 10,000 miles above the visible surface and goes outward for millions of miles. This is the only part of the Sun that can be seen during an eclipse such as the one in February 1979. At any other time, the corona can be seen only when special instruments are used on cameras and telescopes to shut out the glare of the Sun's rays. The corona in brilliant, pearly white, filmy light, about as bright as the full Moon. Its beautiful rays are a sensational sight during an eclipse. The corona' s rays flash out in a brilliant fan that has wispy spike-like rays near the Sun's north and south poles. The corona is thickest at the Sun's equator. The corona rays are made up of gases streaming outward at tremendous speeds and reaching a temperature of more than 2 million degree Fahrenheit. The rays of gas thin out as they reach the space around the planets. By the time the Sun's corona rays reach the Earth, they are weak and invisible.

单选题As he is going to work in Holland for two years, he will be {{U}}parted{{/U}} from his two children.

单选题Earth"s Inner Core Scientists have long struggled to understand what lies at the planet"s center. Direct observation of its center is impossible, so researchers must 1 to other evidence. In 1889, a German scientist detected a severe earthquake in Japan. Geophysicists concluded that shock waves 2 jolts (晃动) from one side of Earth through the center to the other side. Then in 1936, Danish geophysicist Inge Lehmann studied the waves 3 to determine that within Earth"s core of molten (熔化了的) iron lies a solid inner core-but 4 that core was made of eluded (难倒) her. Other geophysicists quickly determined that Lehmann"s inner core was composed mostly 5 iron. Since then, Lehmann"s discovery has 6 conventional Earth science. But now scientists are challenging traditional theory with new and radical 7 . For example, Earth"s center could actually contain an "inner core within the inner core, claim Ishii and colleague Adam Dziewonski. Analyzing hundreds of thousands of earthquake wave 8 , they maintain that the inner core has at its heart a tiny, even more solid sphere (球体). This sphere "may be the oldest fossil 9 from the formation of Earth," says Dziewonski. Dziewonski and Ishii speculate that shortly 10 earth formed around 4.8 billion years ago, a giant asteroid (小行星) smashed into the young planet and nearly melted it. But Earth"s center didn"t quite melt; it 11 mass as the planet cooled. The core within a core may be the kernel (核心) that endured. "Its presence could change our basic ideas about the 12 of the planet," Dziewonski says idea is tame (温和的) compared to the 13 theories of independent geophysicist J. Marvin Herndon. Earth"s inner core is made not of iron, he claims, but a 14 of nickel and silicon. Herndon has a truly revolutionary notion: Within the nickel silicide (硅化物) inner core is also an "inner" inner core—an 8 km—wide ball of the element uranium. Uranium is radioactive. Herndon thinks the uranium releases heat energy as its atoms 15 fission-split and crash into another in a chain reaction. In other words, we may live on top of a gigantic, "natural" nuclear power plant.

单选题His actions do not match his words.A. respond toB. consist toC. correspond toD. accord to

单选题"It's been a privilege to meet you, sir," the young man said to the artist as he was leaving. A. a pleasure B. an ambition C. an honour D. a sad occasion

单选题He is certain that the dictionary is just what I want.

单选题New Foods and the New World In the last 500 years, nothing about people—not their clothes, ideas, or languages—has changed as much as what they eat. The original chocolate drink was made from the seeds of the cocoa tree (可可树) by South American Indians. The Spanish introduced it to the rest of the world during the 1500's. And although it was very expensive, it quickly became fashionable. In London, shops where chocolate drinks were served became important meeting places. Some still exist today. The potato is also from the New World. Around 1600, the Spanish brought it from Peru to Europe, where it soon was widely grown. Ireland became so dependent on it that thousands of Irish people starved when the crop failed during the "Potato Famine (饥荒)" of 1845-1846, and thousands more were forced to leave their homeland and move to America. There are many other foods that have traveled from South America to the Old World. But some others went in the opposite direction. Brazil is now the world's largest grower of coffee, and coffee is an important crop in Colombia and other South American countries. But it is native to Ethiopia, a country in Africa. It was first made into a drink by Arabs during the 1400's. According to an Arabic legend, coffee was discovered when aperson named Kaldi noticed that his goats were attracted to the red berries on a coffee bush. He tried one and experienced the "wide-awake" feeling that one-third of the world's population now starts the day with.

单选题Dolphins are the most useful animals to humans.