单选题Identical twin sisters have led British scientists to a breakthrough in leukemia research that Upromises /Umore effective therapies with fewer harmful side-effects.

单选题The weakened governor could not withstand another catastrophe.

单选题His doctor has told him he mustn't drink, but he still has the occasional brandy______. (2013年3月中国科学院考博试题)

单选题Louis Braille designed a form of communication enabling people to ______ and preserve their thoughts by incorporating a series of dots which were read by the finger tips. A. retain B. visualize C. convey D. transfer

单选题Ever since its discovery, Pluto has never really fitted in. After the pale and glowing giant Neptune, it is little more than a cosmic dust mite, swept through the farthest reaches of the solar system on a planet wildly tilted relative to the rest of the planets. It is smaller than Neptune's largest moon, and the arc of its orbit is so oval that it occasionally crosses its massive blue neighbor's path. For years, it has been seen as our solar system's oddest planet. Yesterday, however, scientists released perhaps the most convincing evidence yet that Pluto, in fact, is not a planet at all. For the first time, astronomers have peered into a belt of rocks beyond Pluto unknown until 10 years ago—and found a world that rivals Pluto in size. The scientists posit that larger rocks must be out there, perhaps even larger than Pluto, meaning Pluto is more likely the king of this distant realm of space detritus than the tiniest of the nine planets. When discovered in 1930, "Pluto at that point was the only thing (that far) out there, so there was nothing else to call it but a planet," says Mike Brown, an astronomer at the California Institute of Technology in Pasadena. "Now it just doesn't fit." In one sense, the question of Pluto's planetary status is arcane, the province of pocket-protected scientists and sun-deprived pen pushers determined to decide some official designation for a ball of dust and ice 3 billion miles away. Yet it is also unquestionably something more. From science fair dioramas to government funding, planets hold a special place in the public imagination, and how Pluto is eventually seen—by kids and Congress alike—could shape what future generations learn about this mysterious outpost on the edge of the solar system. The debate has split the astronomical community for decades. Even before the distant band of rocks known as the Kuiper Belt was found, Pluto's unusual behavior made it suspicious. Elsewhere, the solar system fit into near families: the rocky inner planets, the asteroid belt, the huge and gaseous outer planets. Pluto, though, was peculiar. With the discovery of the Kuiper Belt—countless bits of rock and ice left unused when the wheel of the solar system first formed—Pluto suddenly seemed to have cousins. Yet until yesterday, it held to its planetary distinction because it was far larger than anything located there. The rub now is Quaoar (pronounced KWAH-oar), 1 billion miles beyond Pluto and roughly half as large. Named after the creation force of the tribe that originally inhabited the Los Angeles basin, Quaoar forecasts problems for the erstwhile ninth planet, says discoverer Dr. Brown: "The case is going to get a lot harder to defend the day somebody finds something larger than Pluto," To some, the problem is not with Pluto, but the definition of "planet. "In short, there is none. To the Greeks, who coined the term, it meant "wanderer," describing the way that the planets moved across the night sky differently from the stars behind them. Today, with our more nuanced understanding of the universe, the word no longer has much scientific meaning. New York's Hayden Planetarium caused a commotion two years ago by supposedly demoting Pluto, lumping it with the Kuiper Belt objects in its huge mobile of the solar system. In reality, however, the planetarium was making a much broader statement, says Nell Degrasse Tyson, an astrophysicist there. The textbooks of the future should focus more on families of like objects than "planets." The discovery of Quaoar strengthens this idea. "Everyone needs to rethink the structure of our solar system," he says. "We've just stopped counting planets." Still, many are loath to part with the planet Pluto. They note that Pluto, in fact, is distinct from many Kuiper Belt objects. It has a thin atmosphere, for one. It reflects a great deal of light, while most Kuiper Belt objects are very dark. And unlike all but a handful of known Kuiper Belt objects, it has a moon. "Maybe Pluto, then, should be representative of a new class of planets," says Mark Sykes, an astronomer at the University of Arizona in Tucson. "It's the first example, and we are just beginning to find this category./

单选题Chomsky follows______in philosophy and mentalism in psychology.

单选题She had a good time last night, ______?

单选题The more people are jammed together, the more______and irrational they become.

单选题Talking about that is useless, ______ is familiar to me.

单选题Can you imagine how different your life would be if you did not know how to read and write? Many of the things you (41) for granted during an ordinary day (42) no longer be possible if you could not read. You would miss the basic (43) you depend on for simple activities -- (44) from following instructions on a medicine bottle to (45) traffic signs. If you could not read (46) , newspapers, and magazines, you would be out of (47) with the world around you. Your understanding of that world would be limited even further (48) the insight(见识) provided by stories, poems, and novels. If you (49) not write, you would be unable to record information and ideas for other people. (50) , you would lose the personal pleasure of keeping a (51) to explore your private thoughts, creating an (52) world in a story, or capturing your feelings (53) the words of a poem or song. Try to imagine how different life would be if (54) could read and write. The shape of our entire (55) would change. Obviously the printing and (56) industry would not exist. The absence of reading and writing would (57) a surprising number of other organizations, (58) the automotive industry, the business machines and computer industries, and electronic communication companies. The reason, (59) , is that the printing and publishing industry is a very important part of every one of these organizations. Modem life depends on communication, (60) written communication.

单选题Want a glimpse of the future of health care? Take a look at the way the various networks of people involved in patient care are being connected to one another, and how this new connectivity is being exploited to deliver medicine to the patient-no matter where he or she may be. Online doctors offering advice based on standardized symptoms are the most obvious example. Increasingly, however, remote diagnosis (telemedicine) will be based on real physiological data from the actual patient. A group from the university of Kentucky has shown that by using an off-the shelf (现成的) PDA (personal data assistance) such as a Palm Pilot plus a mobile phone, it is perfectly feasible to transmit a patient's vital signs over the telephone. With this kind of equipment in a first- aid kit (急救包), the cry asking whether there was a doctor in the house could well be a thing of the past. Other medical technology groups are working on applying telemedicine to rural care. And at least one team wants to use telemedicine as a tool for disaster response-especially after earthquakes. Overall, the trend is towards providing global access to medical data and expertise. But there is one problem. Bandwidth is the limiting factor for transmitting complex medical images around the world-CT scans being one of the biggest bandwidth consumers. Communications satellites may be able to cope with the short-term needs during disasters such as earthquakes, wars or famines. But medicine is looking towards both the second-generation internet and third-generation mobile phones for the future of distributed medical intelligence. Doctors have met to discuss computer-based tools for medical diagnosis, training and telemedicine. With the falling price of broadband communications, the new technologies should usher in (迎来) an era when telemedicine and the sharing of medical information, expert opinion and diagnosis are common.

单选题Tom ______ better than to ask Dick for help. A. shall know B. has known C. shouldn't know D. should have known

单选题The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 75 percent hydrogen. Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found in old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic "rays" are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn"t seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same. Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to be significantly greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning. However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperatures were too high and particles of matter were moving around much too rapidly. It was only after the one-minute point that helium could exist. By this time, the universe had cooled sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formation of helium went on for only a relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased.

单选题{{B}}Text 4{{/B}} The U. S. Bureau has estimated that the population of the United States could approach 300 million in 2000 and will be 400 million in 2020. And the U. S. Department of Commerce estimates that the average U.S. per capita income will increase from ＄3400 in 1969 to the equivalent of＄8300(assuming a 1967 price level) in the year 2000,2.5 times as much as that of 1969. According to government statistics, in the United States, there are over 110 million cars and "more people" means "more cars". By the end of twenties of next century, the population of the United States will have doubled that of today and the number of automobiles will be doubled as well. And in twenty-year's time the per capita income will also be 2.5 times higher than it is. If this increase income is spent on more and larger automobiles, larger houses, and increased consumption of other material goods, the results could cause catastrophic resource exhaustion, and pollution. Take the increase of the consumption of oil for instance. The consumption is so huge that the reserves might last only a decade or two if not supplemented by imports. Ten years ago it appeared that nuclear power would solve the anticipated energy crisis. Although supplies of uranium fuel were known to be limited and might become exhausted in half a century, the nuclear power plant has for a long time been a favorite project. But work on it has met with grave problems. The fear of possible atomic explosion and the problem of disposing of polluting by-product waste have slowed down the construction of further nuclear plants. Eventually atomic technology may be able to control these problems, but at present there seems to be little agreement among atomic scientists about when this can be achieved.

单选题When Dr. John W. Gofman, professor of medical physics at the University of California and a leading nuclear critic, speaks of "ecocide" in his adversary view of nuclear technology, he means the following. A large nuclear plant like that in Kalkar, the Netherlands, would produce about 200 pounds of plutonium each year. One pound, released into the atmosphere, could cause 9 billion cases of lung cancer. This waste product must be stored for 500,000 years before it is of no further danger to man. In the anticipated reactor economy, it is estimated that there will be 10,000 tons of this material in Western Europe, of which one table-spoonful of plutonium-239 represents the official maximum permissible body burden for 200,000 people. Rather than being biodegradable, plutonium destroys biological properties. In 1972 the .U.S. Occupational Safety and Health Administration ruled that the asbestos level in the work place should be lowered to 2 fibers per cubic centimeter of air, but the effective date of the ruling has been delayed until now. The International Federation of Chemical and General Workers' Unions report that the 2-fiber standard was based primarily on one study of 290 men at a British asbestos factory. But when the workers at the British factory had been reexamined by another physician, 40--70 percent had X-ray evidence of lung abnormalities. According to present medical information at the factory in question, out of a total of 29 deaths thus far, seven were caused by lung cancer. An average European or American worker comes into contact with six million fibers a day. "We are now, in fact, finding cancer deaths within the family of the asbestos worker," states Dr. Irving Selikoff, of the Mount Sinai Medical School in New York. It is now also clear that vinyl chloride, a gas from which the most widely used plastics are made, causes a fatal cancer of the blood-vessel cells of the liver. However, the history of the research on vinyl chloride is, in some ways, more disturbing than the "Watergate cover- up. " "There has been evidence of potentially serious disease among polyvinyl chloride workers for 25 years that has been incompletely appreciated and inadequately approached by medical scientists and by regulatory authorities," summed up Dr. Selikoff in the New Scientist. At least 17 workers have been killed by vinyl chloride because research over the past 25 years was not followed up. And for over 10 years, workers have been exposed to concentrations of vinyl chloride 10 times the "safe limit" imposed by Dow Chemical Company.

单选题Every year, thousands of college students apply for the CCTV Cup English Speech ______. A. Argument B. Quarrel C. Debate D. Contest

单选题According to the speaker, the basis of British habits of politeness is______.