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David ______ (将公司的成功归因于) the unity of all the staff and their persevering hard work.
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By far the most common snake in Britain is the adder. In Scotland, in fact, there are no other snakes at all. The adder is also the only Britain snake with a poisonous bite. It can be found almost anywhere, but prefers sunny hillsides and rough open country, including high ground. In Ireland there are no snakes at all.Most people regard snake bites as a fatal misfortune, but not all bites are serious, and very few are fatal: Sometimes attempts at emergency treatment turn out to be more dangerous than the bite itself, with amateurs heroically, but mistakenly, trying do-it-yourself surgery and other unnecessary measures.All snakes have small teeth, so it follows that all snakes can bite, but only the bite of the adder presents any danger. British snakes are shy animals and are far more frightened of you than you could possibly be of them. The adder will attack only if it feels threatened, as can happen if you take it by surprise and step on it accidentally, or if you try to catch it or pick it up, which it dislike intensely. If it hears you coming, it will normally get out of the way as quickly as it can, but adders cannot move very rapidly and may attack before moving if you are very close.The effect of a bite varies considerably. It depends upon several things, one of which is the body-weight of the person bitten. The bigger the person, the less harmful the bite is likely to be, which is why children suffer far more seriously from snake bites than adults. A healthy person will also have better resistance against the poison.Very few people actually die from snake bites in Britain, and though these bites can make some people very ill, there are probably just as many cases of bites having little or no effect, as there are of serious illness. If an adder hears you approaching, it will usually ().
The Threat to KiribatiThe people of Kiribati are afraid that one day in the not-too-distant future, their country will disappear from the face of the earth-literally. Several times this year, the Pacific island nation has been flooded by a sudden high tide. These tides, which swept across the island and destroyed houses, came when there was neither wind nor rain. “This never happened before," say the older citizens of Kiribati.What is causing these mysterious high tides The answer may well be global warming. When fuels like oil and coal are being burned, pollutants (污染物) are released; these pollutants trap heat in the earth’s atmosphere. Warmer temperatures cause water to expand and also create more water by melting glaciers (冰川) and polar (级地的) ice caps.If the trend continues, scientists say, many countries will suffer. Bangladesh, for example, might lose one-fifth of its land. The coral (珊瑚) island nations of the Pacific, like Kiribati and the Marshall Islands, however, would face an even worse fate-they would be swallowed by the sea. The loss of these coral islands would be everyone’s loss. Coral formations are home to more species than any other place on earth.The people of these nations feel frustrated. The sea, on which their economies have always been based, is suddenly threatening their existence. They don’t have the money for expensive technological solutions like seawalls. And they have no control over the pollutants, which are being released mainly by activities in large industrialized countries. All they can do is to hope that industrialized countries will take steps to reduce pollution. Some industrialized countries are unwilling to spend money in reducing pollution.()
Cell Phone Lets Your Secret OutYour cell phone holds secrets about you. Besides the names and (51) that you’ve programmed into it, traces of your DNA linger(逗留) on the device, according to a new study.DNA is genetic(遗传的) material that (52) in every cell. Like your fingerprint, your DNA is unique to you (53) you have an identical twin. Scientists today routinely analyze DNA in blood, saliva(涎，唾液), or hair left (54) at the scene of a crime. The results often help detectives identify (55) and their victims. Your cell phone can reveal more about you (56) you might think.Meghan J. McFadden, a scientist at McMaster University in Hamilton, Ontario, heard about a crime in which the suspect bled onto a cell phone and later dropped the (57) This made her wonder whether traces of DNA lingered on cell phones -- even when no blood was involved. (58) she and colleague Margaret Wallace of the City University of New York analyzed the flip-open phones(翻盖手机) of 10 volunteers. They used swabs(药签) to collect (59) traces of the users from two parts of the phone: the outside, where the user holds it, and the (60) , which is placed at the user’s ear.The scientists scrubbed(用力擦洗；擦净) the phones using a solution made mostly (61) alcohol. The aim of washing was to remove all detectable traces of DNA. The owners got their phones(62) for another week. Then the researchers collected the phones and repeated the swabbing of each phone once more.The scientists discovered DNA that (63) to the phone’s speaker on each of the phones. Better samples were collected from the outside of each phone, but those swabs also picked up DNA that belonged to other people who had apparently also handled the phone. (64) , DNA showed up even in swabs that were taken immediately after the phones were scrubbed. That suggests that washing won’t remove all traces of evidence from a criminal’s device. So cell phones can now be added to the (65) of clues that can clinch(确定，决定) a crime-scene investigation. 54（）
Chimpanzees 1. Chimpanzees(黑猩猩)will soon be extinct(灭绝). If the present rate of hunting and habitat(栖息地)destruction continues, then within 20 years,there will be no chimpanzees living in the wild. But this is more than an environmental or moral tragedy(悲剧). Chimpanzee extinction may also have profound implications (含意)for the survival of their distant relatives -- human beings. 2. In 1975 the biologist Marie-Claire King and Allan Wilson discovered that the human and chimpanzee genomes(基因组)match by over 98%. Compare this to the mouse used as model for human disease in lab tests,which shares only 60% of its DNA with us. In fact, chimpanzees are far more similar to humans than they are to any other spectes of monkey. As well as resembling US genetically, chimps are highly intelligent and able to use tools. These facts alone should be enough to make protection of chimps an urgent priority(优先). But there is another,more selfish reason to preserve the chimp. 3. The chimpanzees’trump card(王牌)comes in the field of medical research. Chimpanzees are so similar to humans that veterinarians(兽医) often refer to human medical textbooks when treating them. Yet chimpanzees do show differences in several key areas. In particular, chimps are much more resistant to a number of major diseases. It is this ability that is so interesting. 4. For example,chimps seem to show a much higher resistance than humans to HIV,the virus that causes AIDS. Indeed, their use as experimental animals in AIDS research has declined because they are so resistant. 5. By sequencing the chimp genome and pinpointing(找到)the place where the chimpanzee DNA sequence differs from that of humans, scientists hope to be able to discover which part of the genetic code gives chimps their increased resistance to some diseases. This, they hope, will allow them to develop new and more effective treatments for the human forms of these diseases. Such treatments could include the production of new drugs or even the alteration(改变)of the human genetic sequence. The recently completed human genome sequencing project has shown that such an effort is now well within our reach. A. Genetic Differences Between Chimps and Humans B. Reasons for HIV Resistance C. Implications of Chimpanzee Extinction for Humans D. Effective AIDS Treatment E. Genetic Similarities Between Chimps and Humans F. Chimps’ Resistance to HIV Paragraph 4______
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