单选题The word "it" (Line 3, Paragraph 1 ) denotes

单选题It is implied in the second paragraph that______.

单选题{{B}}Part A{{/B}}{{B}}Text 1{{/B}} At current online-ed rates, it is almost impossible for web publishers that create their own content to make money—just ask any of the two dozen, from Z.com to eCountries that have gone bust in the past month alone. The mason for the bloodbath is simple: advertisers are not willing m pay enough for web ads to support the cost of displaying them. To see why, consider a credit-card firm that wants to find customers online. Say it runs a campaign to display its banner ad to 2 million viewers. Using industry averages, one out of every 200 viewers can be expected to click on the ad: one out of every 100 of those will actually sign up for a credit card. Thus, the campaign would yield 100 new customers. Offline. the firm pays about $150 for each customer it acquires, through anything from direct mail to television ads. Using the same rate, it would therefore be willing to pay $15.000 for those 2 million online-ad views, or a cost-per-thousand- views (CPM) rate of $7.50. Now consider the economics of the website that is running those ads. It probably does not have its own ad sales team, so it is getting those credit-card ads from an advertising network such as DoubleClick. The network takes half the revenues, leaving the site with a CPM of $3.75. Imagine that the site is very successful, say among the top few hundred on the web. If so, it may be able to generate 10m page views 'a month. At $3.75 per thousand views, that means revenue of $37,500 a month. Take out hardware, software and bandwidth costs, and enough might be left to support two employees or so.This grim picture can be improved by selling more than one ad per page. but such clutter often comes at the cost of a lower rate of "click-throughs" and, eventually, even lower CPMs. The site can try to charge higher CPMs by providing more information about viewer demographics, to help advertisers target their ads, or by claiming that it has a sign that may justify a fee for brand-building advertisers. But advertisers are skeptical. The biggest web portals get their content almost for free—a mixture of material from other-sites and content created by viewers—and attract so much traffic that they can support huge organizations on low CPMs. But for most smaller websites, there is no way out. Those that cannot find revenue sources beyond advertising will either go bust or be forced to admit that their site is a non-profit enterprise. If truth-in-advertising rules were enforced, most dotcoms would be dotorgs.

单选题What the author is trying to suggest may be best interpreted as

单选题Most of the illusions that defined the tate global economic boom—the notion that global growth had moved to a non-stop higher plane and housing prices from Miami to Mumbai would rise indefinitely—are now indeed exhausted. Yet one idea still has the power to capture imaginations and markets: it is that commodities like oil, copper, grains and gold are all destined to rise over time. Lots of smart people believe that last year"s increase in commodities prices represented a pause in a long-term bull market. It"s view rooted in powerful and real trends, like the growth of India, the decline in global reserves, fears over resource nationalization and long-term lack of investment in energy and agriculture, which limits supply. At any point in time, there are always new economic powers emerging on the global scene, yet product prices have continued to fall. The 1980s and 1990s were a relatively strong period for the global economy, and India was growing at an average pace of 7 percent. But prices for most commodities did not follow, oil, for example, never broke through the upper limit of $40 a barrel. The reason oil prices did not spike higher is simple: demand for any product is price-elastic, which means that once the price goes too high, consumers stop buying it or make heroic efforts to find a substitute. There is good reason to believe that the world just passed a similar turning point. The last boom in the oil prices collapsed in 1979, when total spending on oil exceeded 7 percent of global GDP. Last year, spending on oil hit a similar share of global GDP, and the price has since fallen by more than two thirds. Yet markets are still betting that the price of oil is poised to spike again. Some analysts predict $90 a barrel by 2012. It"s worth noting that until as recently as 2005, the markets acted on the exact opposite assumption. For years, sport prices ran much higher than futures prices, because most investors assumed prices would follow the historic trend line: down. Today investors are sill reacting to any sign of health in the global economy by pouring money back into commodities, producing the unstable upward price swing we"ve seen in recent weeks.

单选题David Tebbutt is a(n)______ computer expert.

单选题The author's attitude toward most European historian who have studied the Saint-Simonians is primarily one of

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Ours is a society that tries to keep the world sharply divided into masculine and feminine, not because that is the way the world is, but because that is the way we believe it should be. It takes unwavering belief and considerable effort to keep this division. It also leads us to make some fairly foolish judgments, particularly about language. Because we think that language also should be divided into masculine and. feminine we have become very skilled at ignoring anything that will not fit our preconceptions. We would rather change what we hear than change our ideas about the gender division of the world. We will call assertive girls unfeminine, and supportive boys effeminate, and try to ehan4ge them while still retaining our stereotypes of masculine and feminine talk. This is why some research on sex differences and language has been so interesting. It is an illustration of how wrong we can be. Of the many investigators who set out to find the stereotyped sex differences in language, few have had any positive results. It seems that our images of serious taciturn (沉黙的) male speakers and gossipy garrulous (饶舌的)female speakers are just that: images. Many myths associated with masculine and feminine talk have had to be discarded as more research has been undertaken. If females do use more trivial words than males, stop talking in mid-sentence, or talk about the same things over and over again, they do not do it when investigators are around. None of these characteristics of female speech have been found. And even when sex differences have been found, the question arises as to whether the differences is in the eye or ear of the beholder, rather than in the language. If males do not speak in high-pitched voices, it is not usually because they are unable to do so. The reason is more likely to be that there are penalties. Males with high-pitched voices are often the object of ridicule. But pitch is not an absolute, for what is considered the right pitch for males varies from country to country.

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