单选题When mentioning "average annual returns" (Paragraph 5), the author is talking about

单选题That Arctic sea ice is disappearing has been known for decades. The underlying cause is believed by all but a handful of climatologists to be global warming brought about by greenhouse-gas emissions. Yet the rate the ice is vanishing confuses these climatologists' models. These predict that if the level of carbon dioxide, methane and so on in the atmosphere continues to rise, then the Arctic Ocean will be free of floating summer ice by the end of the century. At current rates of shrinkage, by contrast, this looks likely to happen sometime between 2020 and 2050. The reason is that Arctic air is warming twice as fast as the atmosphere as a whole. Some of the causes of this are understood, but some are not. The darkness of land and water compared with the reflectiveness of snow and ice means that when the latter melt to reveal the former, the area exposed absorbs more heat from the sun and reflects less of it back into space. The result is a feedback loop that accelerates local warming. Such feedback, though, does not completely explain what is happening. Hence the search for other things that might assist the ice's rapid disappearance. One is physical change in the ice itself. Formerly a solid mass that melted and refroze at its edges, it is now thinner, more fractured, and so more liable to melt. But that is (literally and figuratively) a marginal effect. Filling the gap between model and reality may need something besides this. The latest candidates are "short-term climate forcings". These are pollutants, particularly ozone and soot (also called "black carbon") that do not hang around in the atmosphere as carbon dioxide does, but have to be renewed continually if they are to have a lasting effect. If they are so renewed, though, their impact may be as big as CO2's. Reducing soot would not stop the summer sea ice disappearing, but it might delay the process by a decade or two. According to a recent report by the United Nations Environment Program, reducing soot and ozone in the lower part of the atmosphere, especially in the Arctic countries of America, Canada, Russia and Scandinavia, could cut warming in the Arctic by two-thirds over the next three decades. Indeed, the report suggests, if such measures—preventing crop burning and forest fires, cleaning up diesel engines and wood stoves, and so on—were adopted everywhere they could halve the wider rate of wanning by 2050. The rapid melting of the Arctic sea ice, then, illuminates the difficulty of modeling the climate—but not in a way that brings much comfort to those who hope that fears about the future climate might prove exaggerated. When reality is changing faster than theory suggests it should, a certain amount of nervousness is a reasonable response.

单选题{{B}}Text 3{{/B}} Search engine Google was aiming to float on Wall Street this week, valued at up to $ 36 billion. But the Internet company's advisers are meeting this weekend to discuss possibly delaying the public listing after a sharp fall in share prices in New York on Friday. An insider said last night:' "The float is teetering on the brink -- it really is 50/50 at this stage, although many of us are optimistic." The initial public offering (IPO) of shares in Google, which could raise nearly $ 4bn, will amount to one of the biggest IPOs for years. But many US firms have shelved their IPOs amid volatile market conditions and investors appear unwilling to subscribe to new equity. A Wall Street analyst said that the Google IPO "would be a seminal event for the American stock market" as its real significance was that it would test whether or not the recovery in equity prices since the end of the Iraq war had taken hold. "If this float works, a lot of other companies will be encouraged and come to the market later in the year," the insider added. "But it will be bad news if the IPO is pulled or the shares fall sharply after the company is listed. If that happens, it could kill off the IPO market in America and elsewhere for at least 12 months." Several fund managers have already expressed reservations about Google, in particular its high valuation and the complex way the shares are being sold. Moreover, the Google flotation is taking place at a time when technology companies in the US have been shunned. On Thursday, the IPO hit a technical hitch over the failure of the company to meet its legal obligations concerning its employees' stock option plans. But the company did not think that the disclosure would mean a delay to the IPO, which is due on Tuesday. At the top of the suggested price range, Google would be valued not far short of its rival Internet firm Yahoo! -- and this has raised eyebrows within the industry. The auction is being conducted over the Internet, and potential buyers will have to register by signing on to a Google website. But only investors who have brokerage accounts with one of the 28 US banks and brokers underwriting the stock sale, will be able to apply. Google suffered a setback last month after it re- ported an unexpected slowdown in its huge growth rate. But sources close to Google's founders, Larry Page and Sergey Brin, said that the tailing-off of growth was due to seasonal factors and would not affect the IPO.

单选题{{B}}Text 4{{/B}} Most economists in the United States seem excited by the spell of the free market. Consequently, nothing seems good or normal that does not accord with the requirements of the free market. A price that is determined by the seller or, for that matter, established by anyone other than the aggregate of consumers seems harmful. Accordingly, it requires a major act of will to think of price-fixing (the determination of prices by the Seller) as both "normal" and having a valuable economic function. In fact, price-fixing is normal in all industrialized societies because the industrial system itself provides, as an effortless consequence of its own development, the price-fixing that it requires. Modern industrial planning requires and rewards great size. Hence, a comparatively small number of large firms will be competing for the same group of consumers. That each large firm will act with consideration of its own needs and thus avoid selling its products for more than its competitors charge is commonly recognized by advocates of free-market economic theories. But each large firm will also act with full consideration of the needs that it has in common with the other large firms competing for the same customers. Each large firm will thus avoid significant price-cutting, because price-cutting would be prejudicial to the common interest in a stable demand for products. Most economists do not see price-fixing when it occurs because they expect it to be brought about by a number of explicit agreements among large firms; it is not. Moreover, those economists who argue that allowing the free market to operate without interference is the most efficient method of establishing prices have not considered the economies of non-socialist countries other than the United States. These economies employ intentional price-fixing, usually in an overt fashion. Formal price-fixing by cartel and informal price-fixing by agreements covering the members of an industry are commonplace. Were there something peculiarly efficient about the free market and inefficient about price-fixing, the countries that have avoided the first and used the second would have suffered drastically in their economic development. There is no indication that they have. Socialist industry also works within a framework of controlled prices. In the early 1970's, the Soviet Union began to give firms and industries some of the flexibility in adjusting prices that a more informal evolution has accorded the capitalist system. Economists in the Unites States have hailed the change as a return to the free market. But Soviet firms are no more subject to prices established by a free market over which they exercise little influence than are capitalist firms; rather, Soviet firms have been given the power to fix prices. {{B}}Notes:{{/B}} spell 魔力; 一阵。aggregate 总体。

单选题The history of modern pollution problems shows that most have resulted from negligence and ignorance. We have an appalling tendency to interfere with nature before all of the possible consequences of our actions have been studied in depth. We produce and distribute radioactive substances, synthetic chemicals and many other potent compounds before fully comprehending their effects on living organisms. Our education is dangerously incomplete. It will be argued that the purpose of science is to move into unknown territory, to explore, and to discover. It can be said that similar risks have been taken before, and that these risks are necessary to technological progress. These arguments overlook an important element. In the past, risks taken in the name of scientific progress were restricted to a small place and brief period of time. The effects of the processes we now strive to master are neither localized nor brief. Air pollution covers vast urban areas. Ocean pollutants have been discovered in nearly every part of the world. Synthetic chemicals spread over huge stretches of forest and farmland may remain in the soil for decades and years to come. Radioactive pollutants will be found in the biosphere for generations. The size and persistence of these problems have grown with the expanding power of modern science. One might also argue that the hazards of modern pollutants are small compared with the dangers associated with other human activity. No estimate of the actual harm done by smog, fallout, or chemical residues can obscure the reality that the risks are being taken before being fully understood. The importance of these issues lies in the failure of science to predict and control human intervention into natural processes. The true measure of the danger is represented by the hazards we will encounter if we enter the new age of technology without first evaluating our responsibility to environment.

单选题Plato asked "What is man?" and St Augustine asked "Who am I?' A new breed of criminals has a novel answer: "I am you!" Although impostors have existed for ages, the growing frequency and cost of identity theft is worrisome. Around 10m Americans are victims annually, and it is the leading consumer-fraud complaint over the past five years. The cost to businesses was almost $50 billion, and to consumers $5 billion, in 2002, the most recent year that America's Federal Trade Commission collected figures. After two recent, big privacy disasters, people and politicians are calling for action. In February, ChoicePoint, a large data-collection agency, began sending out letters warning 145,000 Americans that it had wrongly provided fraudsters with their personal details, including Social Security numbers. Around 750 people have already spotted fraudulent activity. And on February 25th, Bank of America revealed that it lost data tapes that contain personal information on over lm government employees, including some Senators. Although accident and not illegality is suspected, all must take precautions against identity theft. Faced with such incidents, state and national lawmakers are calling for new regulations, including over companies that collect and sell personal information. As an industry, the firms—such as ChoicePoint, Acxiom, LexisNexis and Westlaw—are largely unregulated. They have also grown enormous. For example, ChoicePoint was founded in 1997 and has acquired nearly 60 firms to amass databases with 19 billion records on people. It is used by insurance firms, landlords and even police agencies. California is the only state, with a law requiring companies to notify individuals when their personal information has been compromised—which made ChoicePoint reveal the fraud (albeit five months after it was noticed, and after its top two bosses exercised stock options). Legislation to make the requirement a federal law is under consideration. Moreover, lawmakers say they will propose that rules governing credit bureaus and medical companies are extended to data-collection firms. And alongside legislation, there is always litigation. Already, ChoicePoint has been sued for failing to safeguard individuals' data. Yet the legal remedies would still be far looser than in Europe, where identity theft is also a menace, though less frequent and costly. The European Data Protection Directive, implemented in 1998, gives people the right to access their information, change inaccuracies, and deny permission for it to be shared. Moreover, it places the cost of mistakes on the companies that collect the data, not on individuals. When the law was put in force, American policymakers groaned that it was bad for business. But now they seem to be reconsidering it,

单选题It's a cliche—but true—that a huge obstacle to a stronger economic recovery is the lack of confidence in a strong recovery. If consumers and businesses were more confident, they would be spending, hiring and lending more freely. Instead, we're deluged with reports suggesting that, because the recession was so deep, it will take many years to regain anything like the pre-crisis prosperity. Just last week, for example, the McKinsey Global Institute released a study estimating that the country needs 21 million additional jobs by 2020 to reduce the unemployment rate to 5 percent. The study was skeptical that this would happen. Pessimism and slow growth become a vicious cycle. Battered confidence most obviously reflects the ferocity and shock of the financial collapse and the ensuing recession, including the devastating housing collapse. But there's another, less appreciated cause: disillusion with modern economics. Probably without realizing it, most Americans had accepted the fundamental promises of contemporary economics. These were: First, we know enough to prevent another Great Depression; second, although we can't prevent every recession, we know enough to ensure sustained and, for the most part, strong recoveries. These propositions, endorsed by most economists, had worked themselves into society's belief structure. Embracing them does not preclude economic disappointments, setbacks, worries or risks. But for most people most of the time, it does preclude economic calamity. People felt protected. If you stop believing them, then you act differently. You begin shielding yourself, as best you can, against circumstances and dangers that you can't foresee but that you fear are there. You become more cautious. You hesitate more before making a big commitment-buying a home or car, if you're a consumer; hiring workers, if you're an employer; starting a new business, if you're an entrepreneur; or making loans, if you're a banker. Almost everyone is hunkered down in some way. One disturbing fact from the McKinsey report is this: The number of new businesses, a traditional source of jobs, was down 23 percent in 9,010 from 2007; the level was the lowest since 1983, when America had about 75 million fewer people. Large corporations are standoffish. They have about $2 trillion of cash and securities on their balance sheets, which could be used for hiring and investing in new products. It's not that economics achieved nothing. The emergency measures thrown at the crisis in many countries exceptionally low interest rates, "stimulus" programs of extra spending and tax cuts—probably averted another Depression. But it's also true that there's now no consensus among economists as to how to strengthen the recovery. Economists suffer from what one of them calls "the pretense-of-knowledge syndrome." They act as if they understand more than they do and presume that their policies, whether of the left or right, have benefits more predictable than they actually are. It's worth remembering that the recovery's present slowdown is occurring despite measures taken to speed it up. So modern economics has been oversold, and the public is now disbelieving. The disillusion feeds stubbornly low confidence.

单选题The author made a list of Sachs's positions to show that

单选题What is the expression "knock cheaters off stride" mean?

单选题{{B}}Text 1{{/B}} In 1957 a doctor in Singapore noticed that hospitals were treating an unusual number of influenza-like cases. Influenza is sometimes called “flu” or a “bad cold”. He took samples from the throats of patients in his hospital and was able to find the virus of this influenza. There are three main types of the influenza virus. The most important of these are types A and B, each of them having several sub-groups. With the instruments at the hospital the doctor recognized that the outbreak was due to a virus group A, but he did not know the sub-group. He reported the outbreak to the World Health Organization in Geneva. W. H.O. published the important news alongside reports of a similar outbreak in Hong Kong, where about 15%—20% of the population had become ill. As soon as the London doctors received the package of throat samples, they began the standard tests. They found that by reproducing itself at very high speed, the virus had multiplied more than a million times within two days. Continuing their careful tests, the doctors checked the effect of drugs used against all the known sub-groups of virus type A. None of them gave any protection. This then, was something new: a new influenza virus against which the people of the world had no ready help whatsoever. Having isolated the virus they were working with, the two doctors now dropped it into the noses of some specially selected animals, which contact influenza in the same way as human beings do. In a short time the usual signs of the disease appeared. These experiments revealed that the new virus spread easily, but that it was not a killer. Scientists, like the general public, called it simply “Asian” flu. The first discovery of the virus, however, was made in China before the disease had appeared in other countries. Various reports showed that the influenza outbreak started in China, probably in February of 1957. By the middle of March it had spread all over China. The virus was found by Chinese doctors early in March. But China was not a member of the World Health Organization and therefore did not report outbreaks of disease to it. Not until two months later, when travelers carried the virus into Hong Kong, from where it spread to Singapore, did the news of the outbreak reach the rest of the world. By this time it was started on its way around the world. Thereafter, WHO’s Weekly Reports described the steady spread of this virus outbreak, which within four months swept through every continent.