单选题By what means do the children of the author' s family go to school?

单选题Nuclear fission is the splitting of the nucleus of an atom. Only a few elements are suitable for use in this way, the most important ones being Uranium-235, Uranium-233, and Plutonium-239. When a nucleus of one of these elements is struck by a free neutron it breaks down into two lighter nuclei which fly apart at high speed, colliding with surrounding atoms. Their kinetic energy is converted into heat energy. At the same time, two or three free neutrons are released and one of them enters the nucleus of a neighbouring atom, causing fission to occur again; and so on. The reaction spreads very quickly, with more and more heat energy released. This is called a "chain" reaction because the splitting of each nucleus is linked to another, and another and another. If this reaction takes place in an atomic bomb, where nothing is done to slow it down, the result is a violent explosion that can destroy a town in a few seconds. Fission can also, however, take place within a construction called a nuclear reactor, or atomic pile. Here the highly fissile material (U-235, U-233, Pu-239) is surrounded by a substance that is non-fissile, for instance graphite. This material is called a moderator. The neutrons lose some of their energy and speed through colliding with the atoms of the moderator. Energy—heat energy—is still created on an enormous scale, but no expansion takes place. The moderator has another function: by slowing down the speed of the free neutrons, it makes it more likely that one of them will collide with the nucleus of a neighbouring atom to continue the chain reaction. The chief advantage of nuclear energy is that it does not depend on any local factors. A nuclear reactor, unlike an oil-well or a coalmine, does not have to be sited on top of a fossil-fuel source; unlike the solar energy unit, it does not have to go out of production when the sun is not shining; unlike hydro-electric power, it does not depend on a large flow of water which may be reduced during some seasons of the year. With an atomic power station, the only limiting factor is that of safety. In the opposite process, nuclear fusion, two nuclei come together, to form a new nucleus of a different kind and this process also releases energy on an enormous scale. Fusion can only occur under conditions of very great heat—at least 50000000 degrees Celsius. (The temperature at the centre of the sun is estimated as 130000000 degrees Celsius.) A fusion reaction on earth has already been created—the hydrogen bomb. This is an uncontrolled reaction. It is not yet possible to produce a controlled fusion reaction that can be used for the production of useful energy. Nuclear energy can be thought of as a kind of square, Three of the quarters of the square are known and used, but the fourth cannot yet be used.

单选题Michasson may NOT support the idea to

单选题Which of the following reflects the change of Catholic Church?

单选题Like all the huge metropolises of the world, there are lots of diversions both outdoors and indoors in Chicago. The Art Institute of Chicago has one of the world's (1) art collections, including more French Impressionist paintings than even in the Paris Louvre itself. The Field Museum of Natural History and the Museum of Science and Industry are also great historical and cultural treasure houses to (2) as well as entertain children and adults (3) In the Field Museum one comes (4) a surprisingly big collection of Chinese exhibits from the ancient (5) to the early century. The Sears Tower and the Buckingham Fountain are the pride of the Chicagoans; (6) having 110 storeys is said to be the highest tower in the world and the (7) is the largest fountain in the United States. Lake Michigan is for yachting in summer time, (8) the highlights of Chicago life all the year round are concerts, operas and plays (9) by the city's orchestra, opera houses and theatres. In summer, especially around the Independence Day, July 4th, many festivals and fairs are given outdoors, which, (10) crowds and crowds of people, with their parades, fireworks, (11) concerts, water-skiing and good foods. But with all its attractions and beautiful spots Chicago is also a city (12) for crimes. All the dwelling houses are (13) with three doors and visitors have to speak through microphone (14) in the wall to the residents before they can get admitted. In the streets there are white-color telephones. When one finds oneself (15) , he needs only to knock the receiver (16) the hook and the next instant the police will (17) . If one does not drive a car, it may well be dangerous for him or her to go out alone in the evening. At first I did not take this warning seriously. (18) , my two encounters with the Black people (19) dusk in the neighborhood were so unpleasant and frightening that I have (20) shut myself evenings in my room, in almost all studying, imposing a curfew on myself.

单选题 Music is a mystery. It is unique to the human race: no other species produces elaborate sound for no particular reason. It has been, and remains, part of every known civilization on Earth. Lengths of bone fashioned into flutes were in use 40,000 years ago. And it engages people's attention more comprehensively than almost anything else: scans show that when people listen to music, virtually every area of their brain becomes more active. Yet it serves no obvious adaptive purpose. Charles Darwin, in "'The Descent of Man", noted that "neither the enjoyment nor the capacity of producing musical notes are faculties of the least direct use to man in reference to his ordinary habits of life." Then, what is the point of nmsic. Steven Pinker, a cognitive psychologist, has called music "auditory cheesecake, an exquisite confection crafted to tickle the sensitive spots of at least six of our mental faculties." If it vanished from our species, he said "the rest of our lifestyle would be virtually unchanged." Others have argued that, on the contrary, music, along with art and literature, is part of what makes people human; its absence would have a brutalizing effect. Philip Ball, a British science writer and an avid music enthusiast, comes down somewhere in the middle. He says that music is ingrained in our auditory, cognitive and motor functions. We have a music instinct as much as a language instinct, and could not rid ourselves of it. He goes through each component of music to explain how and why it works, using plentiful examples drawn from a refreshingly wide range of different kinds of music, from Bach to the Beatles, and from nursery rhymes to jazz. His basic message is encouraging and uplifting: people know much more about music than they think. They start picking up the rules from the day they are born, perhaps even before, by hearing it all around them. Very young children can tell if a tune or harmony is not quite right and most adults can differentiate between kinds of music even if they have had no training. Music is completely {{U}}sui generis{{/U}}. It should not tell a non-musical story; the listener will decode it for himself. Many, perhaps most, people have experienced a sudden rush of emotion on hearing a particular piece of music; a thrill or chill, a sense of excitement or exhilaration, a feeling of being swept away by it. They may even be moved to tears, without being able to tell why. Musical analysts have tried hard to find out how this happens, but with little success. Perhaps some mysteries are best preserved.

单选题According to the first paragraph, the grandfather resented

单选题With the spread of inter-active electronic media a man alone in his own home will never have been so well placed to fill the inexplicable mental space between cradle and crematorium. So I suspect that books will be pushed more and more into those moments of travel or difficult defecation (1) people still don't quite know what to do with. When people do read, I think they'll want to feel they are reading literature, or (2) something serious. (3) you're going to find fewer books presenting themselves as no-nonsense and (4) assuming literary pretensions and being packaged as works of art. We can expect an extraordinary variety of genre, but with an underlying (5) of sentiment and vision. Translators can only (6) from this desire for the presumably sophisticated. We can look forward to lots of difficult names and fantastic stories of foreign parts enthusiastically (7) by the overall worship of the "global village". Much of this will be awful and some wonderful, (8) don't expect the press or the organizers of prizes to offer you much help in making the appropriate distinctions. They will be chiefly (9) in creating celebrity, the greatest enemy of discrimination, but a good prop for the (10) consumer. Every ethnic grouping over the world will have to be seen to have a great writer—a phenomenon that will (11) a new kind of provincialism, more chronological than geographic, (12) only the strictly contemporary is talked about and (13) Universities, including Cambridge, will include (14) their literature syllabus novels written only last year. (15) occasional exhumation for the Nobel, the achievements of ten or only five years ago will be largely forgotten. In short, you can't go too far wrong when predicting more of the same. But there is a (16) side to this—the inevitable reaction against it. The practical things I would like to see happen—publishers seeking less to (17) celebrity through extravagant advertising, (18) and magazines (19) space to reflective pieces—are rather more improbable than the Second Coming(耶稣复临). But dullness never quite darkens the whole planet. In their own idiosyncratic fashion a few writers will (20) be looking for new departures.

单选题 For the past two years in Silicon Valley, the centre of America's technology industry, conference-goers have entertained themselves playing a guessing game: how many times will a speaker mention the phrase "long tail"? It is usually a high number, thanks to the influence of the long-tail theory, which was first developed by Chris Anderson, the editor of Wired magazine, in an article in 2004. Though technologists and bloggers chuckle at how every business presentation now has to have its long-tail section, most are envious of Mr. Anderson, whose brainwave quickly became the most fashionable business idea around. Whether a blockbuster film, a bestselling novel, or a chart-topping rap song, popular culture idolises the hit. Companies devote themselves to creating them because the cost of distribution and the limits of shelf space in physical shops mean that profitability depends on a high volume of sales. But around the beginning of this century a group of internet companies realised that with endless shelves and a national or even international audience online they could offer a huge range of products—and make money at the same time. The niche, the obscure and the specialist, Mr. Anderson argues, will gain ground at the expense of the hit. As evidence, he points to a drop in the number of companies that traditionally calculate their revenue/sales ratio according to the 80/20 rule—where the top fifth of products contribute four-fifths of revenues. Ecast, a San Francisco digital jukebox company, found that 98% of its 10000 albums sold at least one track every three months. Expressed in the language of statistics, the experiences of Ecast and other companies such as Aragon, an online bookseller, suggest that products down in the long tail of a statistical distribution, added together, can be highly profitable. The internet helps people find their way to relatively obscure material with recommendations and reviews by other people, (and for those willing to have their artistic tastes predicted by a piece of software) computer programs which analyse past selections. Long-tail enthusiasts argue that the whole of culture will benefit, not just commercial enterprises. Television, film and music are such bewitching media in their own right that many people are quite happy to watch and listen to what the mainstream provides. But if individuals have the opportunity to pick better, more ideally suited entertainment from a far wider selection, they will take it, according to the theory of the long tail. Some analysts reckon that entire populations might become happier and wiser once they have access to thousands of documentaries, independent films and subgenres of every kind of music, instead of being subjected to what Mr. Anderson calls the tyranny of lowest-common-denominator fare. That might be taking things a bit far. But the long tail is certainly one of the internet's better gifts to humanity.

单选题In relation to the "writers on management" mentioned in Para. 2, the text suggests that they

单选题 Attempts to understand the relationship between social behavior and health have their origin in history. Dubos (1969) suggested that primitive humans were closer to the animals{{U}} {{U}} 1 {{/U}} {{/U}}they, too, relied'upon their instincts to stay healthy. Yet some primitive humans{{U}} {{U}} 2 {{/U}} {{/U}}a cause and effect relationship between doing certain things and alleviating{{U}} {{U}} 3 {{/U}} {{/U}}of a disease or{{U}} {{U}} 4 {{/U}} {{/U}}the condition of a wound.{{U}} {{U}} 5 {{/U}} {{/U}}there was so much that primitive humans did not{{U}} {{U}} 6 {{/U}} {{/U}}the functioning of the body, magic became an integral component ofthe beliefs about the causes and cures of heath{{U}} {{U}} 7 {{/U}} {{/U}}Therefore it is not{{U}} {{U}} 8 {{/U}} {{/U}}that early humans thought that illness was caused{{U}} {{U}} 9 {{/U}} {{/U}}evil spirit. Primitive medicines made from vegetables or animals were invariably used in combination with some form of ritual to{{U}} {{U}} 10 {{/U}} {{/U}}harmful spirit from a diseased body. One of the. earliest{{U}} {{U}} 11 {{/U}} {{/U}}in the Western world to formulate principles of health care based upon rational thought and{{U}} {{U}} 12 {{/U}} {{/U}}of supernatural phenomena is found in the work of the Greek physician Hippocrates. The writing{{U}} {{U}} 13 {{/U}} {{/U}}to him has provided a number of principles underiying modern medical practice. One of his most famous{{U}} {{U}} 14 {{/U}} {{/U}}, the Hippocratic Oath, is the foundation of contemporary medical ethics. Hippocrates also argued that medical knowledge should be derived from a{{U}} {{U}} 15 {{/U}} {{/U}}of the natural science and the logic of cause and effect relationships. In this{{U}} {{U}} 16 {{/U}} {{/U}}thesis, On Air, Water, and Places, Hippocrates pointed out that human well-being is{{U}} {{U}} 17 {{/U}} {{/U}}by the totality of environmental{{U}} {{U}} 18 {{/U}} {{/U}}: living habits or lifestyle, climate, geography of the land, and the quality of air, and food.{{U}} {{U}} 19 {{/U}} {{/U}}enough, concerns about our health and the quality of air, water, and places are{{U}} {{U}} 20 {{/U}} {{/U}}very much written in twentieth century.

单选题The word "reading" in ( Line 3,Paragraph 2) denotes

单选题{{B}}Text 2{{/B}} Saudi Arabia, the oil industry's swing producer, has become its flip-flopper. In February, it persuaded OPEC to cut its total production quotas by lm barrels per day (bpd), to 23.5m, as a precaution against an oil-price crash this spring. That fear has since been replaced by its opposite. The price of West Texas crude hit $40 last week, its highest since the eve of the first Iraq war, prompting concerns that higher oil prices could sap the vigour of America's recovery and compound the frailty of Europe's. On Monday May 10th, Ali al-Naimi, Saudi Arabia's energy minister, called on OPEC to raise quotas, by at least 1. 5m bpd, at its next meeting on June 3rd. Thus far, the high oil price has been largely a consequence of good things, such as a strengthening world economy, rather than a cause of bad things, such as faster inflation or slower growth. China's burgeoning economy guzzled about 6m bpd in the first quarter of this year, 15% more than a year ago, according to Goldman Sachs. Demand was also strong in the rest of Asia, excluding Japan, growing by 5.2% to 8. 1m bpd. As the year progresses, the seasonal rhythms of America's drivers will dictate prices, at least of the lighter, sweeter crudes. Americans take to the roads en masse in the summer, and speculators are driving up the oil price now in anticipation of peak demand in a few months' time. Until recently, the rise in the dollar price of oil was offset outside America and China by the fall in the dollar itself. But the currency has regained some ground in recent weeks, and the oil price has continued to rise. Even so, talk of another oil price shock is premature. The price of oil, adjusted for inflation, is only half what it was in December 1979, and the United States now uses half as much energy per dollar of output as it did in the early 1970s. But if oil cannot shock the world economy quite as it used to, it can still give it "a good kick", warns Goldman Sachs. If average oil prices for the year come in 10% higher than it forecast, it reckons GDP growth in the Group of Seven (G7) rich nations will be reduced by 0.3%, or $70 billion. The Americans are certainly taking the issue seriously. John Snow, their treasury secretary, called OPEC's February decision "regrettable", and the rise in prices since then "not helpful". Washington pays close heed to the man at the petrol pump, who has seen the average price of a gallon of unleaded petrol rise by 39 cents in the past year. And the Saudis, some mutter, pay close heed to Washington. Besides, the high oil price may have filled Saudi coffers, but it has also affronted Saudi pride. Mr. al-Naimi thinks the high price is due to fears that supply might be disrupted in the future. These fears, he says, are "unwarranted". But the hulking machinery in the Arabian desert that keeps oil flowing round the world presents an inviting target to terrorists should they tire of bombing embassies and nightclubs. (ha May 1st, gunmen killed six people in a Saudi office of ABB Lummus Global, an American oil contractor. Such incidents add to the risk premium factored into the oil price, a premium that the Saudis take as a vote of no confidence in their kingdom and its ability to guarantee the supply of oil in the face of terrorist threats.

单选题The author thinks current entertainment is relatively poor because