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When prehistoric man arrived in new parts of the world, something strange happened to the large animals. They suddenly became extinct. Smaller species survived. The large, slow-growing animals were easy game, and were quickly hunted to extinction. Now something similar could be happening in the oceans.That the seas are being over fished has been known for years. What researchers such as Ransom Myers and Boris Worm have shown is just how fast things are changing. They have looked at half a century of data from fisheries around the world. Their methods do not attempt to estimate the actual biomass (the amount of living biological matter) of fish species in particular parts of the ocean, but rather changes in that biomass over time. According to their latest paper published in Nature, the biomass of large predators (animals that kill and eat other animals) in a new fishery is reduced on average by 80% within 15 years of the start of exploitation. In some long-fished areas, it has halved again since then.Dr. Worm acknowledges that these figures are conservative. One reason for this is that fishing technology has improved. Today’s vessels can find their prey using satellites and sonar, which were not available 50 years ago. That means a higher proportion of what is in the sea is being caught, so the real difference between present and past is likely to be worse than the one recorded by changes in catch sizes. In the early days, too, longlines would have been more saturated with fish. Some individuals would therefore not have been caught, since no baited hooks would have been available to trap them, leading to an underestimate of fish stocks in the past. Furthermore, in the early days of longline fishing, a lot of fish were lost to sharks after they had been hooked. That is no longer a problem, because there are fewer sharks around now.Dr. Myers and Dr. Worm argue that their work gives a correct baseline, which future management efforts must take into account. They believe the data support an idea current among marine biologists, that of the "shifting baseline. " The notion is that people have failed to detect the massive changes which have happened in the ocean because they have been looking back only a relatively short time into the past. That matters because theory suggests that the maximum sustainable yield that can be cropped from a fishery comes when the biomass of a target species is about 50% of its original levels. Most fisheries are well below that, which is a bad way to do business. We can infer from Dr. Myers and Dr. Worm’s paper that ().
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Historically, humans get serious about avoiding disasters only after one has just struck them. (21) that logic, 2006 should have been a breakthrough year for rational behavior. With the memory of 9/11 still (22) in their minds, Americans watched hurricane Katrina, the most expensive disaster in U.S. history, on (23) TV. Anyone who didn’t know it before should have learned that bad things can happen. And they are made (24) worse by our willful blindness to risk as much as our (25) to work together before everything goes to hell.Granted, some amount of delusion (错觉) is probably part of the (26) condition. In A.D. 63, Pompeii was seriously damaged by an earthquake, and the locals immediately went to work (27) , in the same spot—until they were buried altogether by a volcano eruption 16 years later. But a (28) of the past year in disaster history suggests that modern Americans are particularly bad at (29) themselves from guaranteed threats. We know more than we (30) did about the dangers we face. But it turns (31) that in times of crisis, our greatest enemy is (32) the storm, the quake or the (33) itself. More often, it is ourselves.So what has happened in the year that (34) the disaster on the Gulf Coast In New Orleans, the Army Corps of Engineers has worked day and night to rebuild the flood walls. They have got the walls to (35) they were before Katrina, more or less. That’s not (36) , we can now say with confidence. But it may be all (37) can be expected from one year of hustle (忙碌).Meanwhile, New Orleans officials have crafted a plan to use buses and trains to (38) the sick and the disabled. The city estimates that 15, 000 people will need a (39) out. However, state officials have not yet determined where these people will be taken. The (40) with neighboring communities are ongoing and difficult. 21().
A report consistently brought back by visitors to the US is how friendly, courteous and helpful most Americans were to them. To be fair, this observation is also frequently made of Canada and Canadians, and should best be considered North American. There are, of course, exceptions. Small-minded officials, rude waiters, and ill-mannered taxi drivers are hardly unknown in the US. Yet it is an observation made so frequently that it deserves comment. For a long period of time and in many parts of the country, a traveler was a welcome break in an otherwise dull existence.Dullness and loneliness were common problems of the families who generally lived distant from one another. Strangers and travelers were welcome sources of diversion, and brought news of the outside world. The harsh realities of the frontier also shaped this tradition of hospitality.Someone traveling alone, if hungry, injured, or ill, often had nowhere to turn except to the nearest cabin or settlement. It was not a matter of choice for the traveler or merely a charitable impulse on the part of the settlers. It reflected the harshness of daily life: if you didn’t take in the stranger or take care of him, there was no one else who would. And someday, remember, you might be in the same situation. Today there are many charitable organizations which specialize in helping the weary traveler. Yet, the old tradition of hospitality to strangers is still very strong in the US, especially in the smaller cities and towns away from the busy tourist trails. "I was just traveling through, got talking with this American, and pretty soon he invited me home for dinner-amazing. " Such observations reported by visitors to the US are not uncommon, but are not always understood properly.The casual friendliness of many Americans should be interpreted neither as superficial nor as artificial, but as the result of a historically developed cultural tradition. As is true of any developed society, in America a complex set of cultural signals, assumptions, and conventions underlies all social interrelationships. And, of course, speaking a language does not necessarily mean that someone understands social and cultural patterns. Visitors who fail to "translate" cultural meanings properly often draw wrong conclusions. For example, when an American uses the word "friend", the cultural implications of the word may be quite different from those it has in the visitor’s language and culture. It takes more than a brief encounter on a bus to distinguish between courteous convention and individual interest. Yet, being friendly is a virtue that many Americans value highly and expect from both neighbors and strangers. In the eyes of visitors from the outside world, ().
Obtaining good health insurance is a real necessity while you are studying overseas. It protects you from minor and major medical expenses that can wipe out not only your savings but your dreams of an education abroad. There are often two different types of health insurance you can consider buying, international travel insurance and student insurance in the country where you will be going.An international travel insurance policy is usually purchased in your home country before you go abroad. It generally covers a wide variety of medical services and you are often given a list of doctors in the area where you will travel who may even speak your native language. The drawback might be that you may not get your money back immediately, in other words, you may have to pay all your medical expenses and then later submit your receipts to the insurance company.On the other hand, getting student health insurance in the country where you will study might allow you to only pay a certain percentage of the medical cost at the time of service and thus you don’t have to have sufficient cash to pay the entire bill at once. Whatever you decide, obtaining some form of health insurance is something you should consider before you go overseas. You shouldn’t wait until you are sick with major medical bills to pay off. Why does the speaker advice overseas students to buy health insurance().
Publicity offers several benefits. There are no costs for message time or space. An ad in prime-time television may cost $ 250, 000 to $ 5, 000, 000 or more per minute, whereas a five-minute report on a network newscast would not cost anything. However, there are costs for news releases, a publicity department, and other items. As with advertising, publicity reaches a mass audience. Within a short time, new products or company policies are widely known.Credibility about messages is high, because they are reported in independent media. A newspaper review of a movie has more believability than an ad in the same paper, because the reader associates independence with objectivity. Similarly, people are more likely to pay attention to news reports than to ads. For example, Women’s Wear Daily has both fashion reports and advertisements. Readers spend time reading the stories, but they flip through the ads. Furthermore, there may be 10 commercials during a half-hour television program or hundreds of ads in a magazine. Feature stories are much fewer in number and stand out clearly.Publicity also has some significant limitations. A firm has little control over messages, their timing, their placement, or their coverage by a given medium. It may issue detailed news releases and find only portions cited by the media, and media have the ability to be much more critical than a company would like.For example, in 1982, Procter ＆ Gamble faced a substantial publicity problem over the meaning of its 123-year-old company logo. A few ministers and other private citizens believed resulted in the firm receiving 15, 000 phone calls about the rumor in June alone. To combat this negative publicity, the firm issued news releases featuring prominent clergy that refuted the rumors, threatened to sue those people spreading the stories, and had a spokesperson appear on Good Morning America. The media cooperated with the company and the false rumors were temporarily put to rest. However, in 1985, negative publicity became so disruptive that Procter ＆ Gamble decided to remove the logo from its products.A firm may want publicity during certain periods, such as when a new product is introduced or a new store is opened, but the media may not cover the introduction or opening until after the time it would aid the firm. Similarly, media determine the placement of a story: it may follow a report on crime or sports. Finally, the media ascertain whether to cover a story at all and the amount of coverage to be devoted to it. A company-sponsored fobs program might go unreported or receive three-sentence coverage in a local newspaper. According to the passage, which of the following statements is true().
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