单选题The statement"... but made a vast number of 35-year-olds redundant" in the last paragraph refers to the fact that?

单选题The word "deter" in the last paragraph probably means ______

单选题As pointed out in the text, the video art technology is characterized by its

单选题 The technology revolution may be coming to poor countries via the mobile phone, not the personal computer, as it did in rich ones. And just as the Internet encouraged an entrepreneurial philosophy, and with it the creation of a few too many dotcom firms, Africa's surge in mobile-phone use may {{U}}unleash{{/U}} the same sort of business energy, but tailored to local needs. One such initiative is about to begin. TradeNet, a software company based in Accra, Ghana, will unveil a simple sort of eBay for agricultural products across a dozen countries in West Africa. It lets buyers and sellers indicate what they are after and their contact information, which is sent to all relevant subscribers as an SMS text message in one of four languages. Interested parties can then reach others directly to do a deal. Listing offers is free, as is receiving the texts. TradeNet plans to earn revenue by putting advertisements in the messages, though it hopes the service will become so useful that recipients will eventually want to pay. For the moment, though, the company is busy signing up users and swallowing the cost of sending the messages. Mobile-phone use in sub-Saharan Africa is soaring. Whereas only 10% of the population had network coverage in 1999, today more than 60% have it, a figure expected to exceed 85% in the coming year, according to the GSM Association, an industry trade group. This provides the infrastructure for businesses like TradeNet to function. TradeNet is the brainchild of Mark Davies, a British dotcom tycoon who gave up the rat race and went to Africa in 2000. In 2005, he started the prototype for TradeNet using around ＄600,000 of his own money and about ＄200,000 from aid agencies. An early set of trials last year generated a surplus of trades, such as a sale of organic fertilizer between a person in Yemen and another in Nigeria. A number of other mobile-phone market-places taking shape also started as aid projects. For example, Trade at Hand, a project funded by the UN's International Trade Centre in Geneva, provides daily price information for fruit and vegetable exports in Burkina Faso and Mali, with plans to add more countries. And Manobi, a telecoms firm based in Senegal, providing real-time agricultural and fish prices to fee-paying subscribers, is also backed by aid money. But TradeNet's approach is unique so far because it collects valuable economic data-names, locations, business interests and telephone numbers-and then sells them to advertisers. The price of economic development may be junk mail by mobile phone.

单选题Americans no longer expect public figures, whether in speech or in writing, to command the English language with skill and gift. Nor do they aspire to such command themselves. In his latest book, Doing Our Own Thing: The Degradation of Language and Music and Why We Should, Like, Care , John McWhorter, a linguist and controversialist of mixed liberal and conservative views, sees the triumph of 1960s counter-culture as responsible for the decline of formal English. Blaming the permissive 1960s is nothing new, but this is not yet another criticism against the decline in education. Mr. McWhorter"s academic speciality is language history and change, and he sees the gradual disappearance of "whom", for example, to be natural and no more regrettable than the loss of the case-endings of Old English. But the cult of the authentic and the personal, "doing our own thing", has spelt the death of formal speech, writing, poetry and music. While even the modestly educated sought an elevated tone when they put pen to paper before the 1960s, even the most well regarded writing since then has sought to capture spoken English on the page. Equally, in poetry, the highly personal, performative genre is the only form that could claim real liveliness. In both oral and written English, talking is triumphing over speaking, spontaneity over craft. Illustrated with an entertaining array of examples from both high and low culture, the trend that Mr. McWhorter documents is unmistakable. But it is less clear, to take the question of his subtitle, why we should, like, care. As a linguist, he acknowledges that all varieties of human language, including non-standard ones like Black English, can be powerfully expressive—there exists no language or dialect in the world that cannot convey complex ideas. He is not arguing, as many do, that we can no longer think straight because we do not talk proper. Russians have a deep love for their own language and carry large chunks of memorized poetry in their heads, while Italian politicians tend to elaborate speech that would seem old-fashioned to most English-speakers. Mr. McWhorter acknowledges that formal language is not strictly necessary, and proposes no radical education reforms—he is really grieving over the loss of something beautiful more than useful. We now take our English "on paper plates instead of china". A shame, perhaps, but probably an inevitable one.

单选题It never rains but it pours. Just as bosses and boards have finally sorted out their worst accounting and compliance troubles, and improved their feeble corporation governance, a new problem threatens to earn them -- especially in American--the sort of nasty headlines that inevitably lead to heads rolling in the executive suite: data insecurity. Left, until now, to odd, low-level IT staff to put right, and seen as a concern only of data-rich industries such as banking, telecoms and air travel, information protection is now high on the boss's agenda in businesses of every variety. Several massive leakages of customer and employee data this year-- from organizations as diverse as Time Warner, the American defense contractor Science Applications International Corp and even the University of California, Berkeley——have left managers hurriedly peering into their intricate IT systems and business processes in search of potential vulnerabilities. "Data is becoming an asset which needs to be guarded as much as ally other asset," says Haim Mendelson of Stanford University's business school. "The ability to guard customer data is the key to market value, which the board is responsible for on behalf of shareholders". Indeed, just as there is the concept of Generally Accepted Accounting Principles (GAAP), perhaps it is time for GASP. Generally Accepted Security Practices, suggested Eli Norm of New York's Columbia Business School. "Setting the proper investment level for security, redundancy, and recovery is a management issue, not a technical one." he says. The mystery is that this should come as a surprise to any boss. Surely it should be obvious to the dimmest executive that trust, that most valuable of economic assets, is easily destroyed and hugely expensive to restore -- and that few things are more likely to destroy trust than a company letting sensitive personal data get into the wrong hands. The current state of affairs may have been encouraged -- though not justified-- by the lack of legal penalty (in America, but not Europe) for data leakage. Until California recently passed a law, American firms did not have to tell anyone, even the victim, when data went astray. That may change fast: lots of proposed data-security legislation is now doing the rounds in Washington, D.C. Meanwhile, the theft of information about some 40 million credit-card accounts in America, disclosed on June 17th, overshadowed a hugely important decision a day earlier by America's Federal Trade Commission (FTC) that puts corporate America on notice that regulators will act if firms fall to provide adequate data security.

单选题We learn from the passage that dot-com companies

单选题 It seems to happen with depressing frequency-surely skies turn to rain just as the weekend arrives. Now Spanish researchers say they have evidence that in some parts of Europe the weather really does follow a weekly cycle, although not in the straightforward way that the anecdote might suggest. Evidence has been mounting over the years that the weather in certain parts of the world, including the US, Japan and China, can be driven by the weekly cycle of human activity. This is because we tend to produce more air pollution during the week and less at the weekend. Evidence that such an effect occurs in Europe is controversial and has been harder to come by. Arturo Sanchez-Lorenzo of the University of Barcelona, Spain, and his colleagues examined data gathered between 1961 and 2004 from weather stations across Spain to see whether such a pattern existed. They claim to have found it in Spain, as well as hints of weekly changes in air circulation more broadly over Western Europe. The result is puzzling, but it is known that airborne pollutants produced by human activity can affect the weather in a variety of ways. For example, particles can be heated by absorbing sunlight, which in turn heats the air and changes air circulation patterns. Pollutant particles can also provide seeds for cloud formation. Exactly which effect has the greatest influence seems to depend on conditions that vary season by season. They also found signs that air pressure in Western Europe tends to be lower midweek than at the weekend in data from a global database. This suggests that the human influence on weather goes beyond known local effects, says team member Josep Calbó of the University of Girona in Spain. However, it is not clear whether the team's findings are statistically significant, says Thomas Bell of NASA's Goddard Space Flight Center in Greenbelt, Maryland, who was part of a team that found a stronger weekly cycle in the US. "This whole enterprise of looking for weekly cycles is rife with possibilities for misleading oneself." Why a weekly cycle would be less noticeable in Europe than in the US and Asia is still unknown. No weekly cycle has ever been found in the UK, probably because the weather is dominated by large systems blowing in from the Atlantic Ocean. These larger systems may be harder for weekly pollution cycles to influence, points out Douglas Maraun of the University of East Anglia in Norwich, who studies UK precipitation. "I doubt that there is a weekly influence of human activity on such a large weather system," he says.

单选题Why does the author mention the visible-light microscope in the first paragraph?

单选题In the Gilded Age, people who possessed a calling card______

单选题{{B}}Text 3{{/B}} This line of inquiry did not begin until earlier this month--more than three months after the accident--because there were "too many emotions, too many egos," said retired Adm. Harold Gehman, chairman of the Columbia Accident Investigation Board. Testifying before the Senate Commerce Committee, Gehman said this part of his inquiry Was in its earliest stages, starting just 10 days ago. But Gehman said he already has concluded it is "inconceivable" that NASA would have been unable or unwilling to attempt a rescue for astronaut, s in orbit if senior shuttle managers and administrators had known there was fatal damage to Columbia's left wing. Gehman told reporters after the hearing that answers to these important questions could have enormous impact, since they could place in a different context NASA's decisions against more aggressively checking possible wing damage in the days before Columbia's fatal return. Investigators believe breakaway insulating foam damaged part of Columbia's wing Shortly after liftoff, allowing superheated air to penetrate the wing during its fiery re-entry on Feb. 1 and melt it from the inside. Among those decisions was the choice by NASA's senior shuttle managers and administrators to reject offers of satellite images of possible damage to Columbia's left wing before the accident. The subject dominated the early part of Wednesday's hearing. Gehman complained that managers and administrators "missed signals" when they rejected those offers for images, a pointedly harsh assessment of the space agency's inaction during the 16 day shuttle mission. "We will attempt to pin this issue down in our report, but there were a number of bureaucratic and administrative missed signals here," Gehman told senators. "We're not quite so happy with the process." The investigative board already had recommended that NASA push for better coordination between the space agency and military offices in charge of satellites and telescopes. The U. S. National Imagery and Mapping Agency in March agreed to regularly capture detailed satellite images of space shuttles in orbit. Still, Gehman said it was unclear whether even images from America's most sophisticated spy satellites might have detected on Columbia's wing any damage, which Gehman said could have been as small as two inches square. The precise capabilities of such satellites was a sensitive topic during the Senate hearing.

单选题Which statement is NOT true according to para. 2?______.

单选题Arsenic, a naturally occurring poison and carcinogen found in ground water, is strongly linked to adult-onset diabetes, U. S. researchers said on Tuesday. Odorless, tasteless, colorless and easily soluble in water or wine, arsenic has long been a feared poison. A heavy dose is detectable in a corpse, but researchers say small amounts of arsenic may sicken people gradually. Dr. Ana Navas-Aeien and colleagues at Johns Hopkins University in Baltimore found a " relatively strong " association between commonly found levels of arsenic in urine and type 2 diabetes in a study of American adults. " It seems there is maybe no safe level of arsenic. " Navas-Acien said in a telephone interview. " Worldwide it's a huge problem, " she said. " As water becomes a scarce resource. the situation becomes even more serious. " Arsenic raises the risk for cancers of the bladder, lung, kidney, skin and, possibly, the pros tate, Navas-Acien said. The 20 percent of nearly 800 study participants who had the most arsenic in their bodies, a tolerable 16. 5 micrograms per liter of urine, had 3. 6 times the risk of developing late-onset diabetes than those in the bottom 20 percent, who had 3 micrograms per liter. Levels of arsenic were 26 percent higher in people with late-onset, or type 2, diabetes than those without the disease, the study found. The U. S. government sets a limit for drinking water at 10 micrograms of arsenic per liter, which is exceeded in the water consumed by 13 million Americans who mostly live in rural areas that rely on wells to bring up ground water, the researchers wrote in the Journal of the American Medical Association. Arsenic contaminates drinking water for millions of people in Bangladesh, parts of Central Europe, Chile, Argentina and the western United States, where ground water is the source of drinking water and the land has higher concentrations of arsenic. Overall, 7. 8 percent of Americans are believed to have diabetes, although some do not know it. At least 90 percent of cases are the type 2 variety, in which the body loses its ability to use insulin properly. Navas-Acien said arsenic may play a significant role in diabetes incidence, but it is difficult to say how much. Arsenic can accumulate in the body, and can ruin the body's ability to use insulin and perform the vital task of converting blood sugar into energy. Normally, insulin fits into cells via molecular doorways called receptors, which in turn signal the cell to move glucose inside, but arsenic enters the cell and somehow blocks the activity. Seafood is another source of arsenic, but the organic form found in shellfish and some fish has a carbon molecule attached and poses no risk to health, she said.