题目内容
Passage Five What produces a waterproof super glue, acts like a vacuum cleaner, and even teaches scientists about gene repair The humble little shellfish known as the mussel (贻贝)。 Mussels are found worldwide. Some live in the sea. Others inhabit freshwater streams and lakes. When you try to move a mussel from a rock, you will discover what an incredibly firm grip it has- a necessity if the mussel is to resist the sharp grab of a hungry seabird or the pounding waves of the sea. How does it manage to cling so tight When it choose a place to set up home, it pokes its tongue-shaped foot out of its shell and presses it against a solid surface. Special glands give off a fluid mixture of proteins into a channel that runs the length of the foot. The liquid quickly hardens into a fine, elastic thread about an inch long. Then a tiny pad-like structure at the end of this thread gives off some natural glue-like substance, the mussel lifts its foot, and anchor line number one is complete. These strategically placed threads form a bundle, which ties the mussel to its new home in much the same way that ropes hold down a tent. The whole procedure takes only three or four minutes. Imagine having a very strong glue that is non-toxic and so flexible that it can penetrate the tiniest holes and corners, sticking to any surface, even under water. Shipbuilders would welcome it for repairing vessels without the expense of dry-docking them. Auto-body workers would like a really waterproof paint that keeps the rust out. Surgeons would value a safe glue to join broken bones and to close wounds... The list of possible uses appears endless. However, scientists are not thinking of using the mussels themselves to produce this super glue. It would take some l0.000 shellfish to make just one gram of glue. So collection enough mussels to supply the world’s demand for super glue would wipe out the mussel population, many species of which are already endangered. Instead, American researchers have isolated and cloned the genes for five mussel glue proteins, and they are about to mass-produce them in the laboratory. However, the mussel is still one jump ahead. Only the mussel instinctively knows the exact blend of proteins needed for each kind of surface. Molecular biologist Frank Roberto has asked admiringly: "How are you ever going to imitate that" The main idea of this passage is that ______
查看答案
搜索结果不匹配？点我反馈
更多问题
Passage Three The average number of authors on scientific papers is sky-rocketing. That’s partly because labs are bigger, problems are more complicated, and more different subspecialties are needed. But it’s also because U.S. government agencies have started to promote "team science". As physics developed in the post-World War II era, federal funds built expensive national facilities, and these served as surfaces on which collaborations could crystallize naturally. Yet multiple authorship—however good it may be in other ways--presents problems for journals and for the institutions in which these authors work. For the journals, long lists of authors are hard to deal with in themselves. But those long lists give rise to more serious questions when something goes wrong with the paper. If there is research misconduct, how should the liability be allocated among the authors If there is an honest mistake in one part of the work but not in others, how should an evaluator aim his or her review Various practical or impractical suggestions have emerged during the long-standing debate on this issue. One is that each author should provide, and the journal should then publish, an account of that author’s particular contribution to the work. But a different view of the problem, and perhaps of the solution, comes as we get to university committee on appointments and promotions, which is where the authorship rubber really meets the road. Half a lifetime of involvement with this process has taught me how much authorship matters. I have watched committees attempting to decode sequences of names, agonize over whether a much-cited paper was really the candidate’s work or a coauthor’s, and send back recommendations asking for more specificity about the division of responsibility. Problems of this kind change the argument, supporting the case for asking authors to define their own roles. After all, if quality judgments about individuals are to be made on the basis of their personal contributions, then the judges better know what they did. But if questions arise about the validity of the work as a whole, whether as challenges to its conduct or as evaluations of its influence in the field, a team is a team, and the members should share the credit or the blame. According to the passage, there is a tendency that scientific papers ______
In recent years a new farming revolution has begun, one that involves the (61) of life at a fundamental level--the gene. The study of genetics has (62) a new industry called biotechnology. As the name suggests, It (63) biology and modern technology through such techniques as genetic engineering. Some of the new biotech companies specialize in agriculture and are working feverishly to (64) seeds that give a high yield, that (65) diseases, drought and frost, and that reduce the need for (66) chemicals. If such goals could be achieved, it would be most (67) . But some have raised concerns about genetically engineered crops. In nature, genetic diversity is created within certain (68) . A rose can be crossed with a different kind of rose, but a rose will never cross with a potato. Genetic engineering, (69) usually involves taking genes from one species and inserting them into another (70) to transfer a desired characteristic. This could mean, for example, selecting a gene which leads to the production of a chemical with anti-freeze (71) from an artic fish, and inserting it into a potato or strawberry to make it frost-resistant. (72) , then, biotechnology allows humans to (73) the genetic wails that separate species. Like the green revolution, (74) some call the gene revolution contributes to the problem of genetic uniformity--some say even more so (75) geneticists can employ techniques such as cloning and (76) culture (培养), processes that produce perfectly (77) copies. Concerns about the erosion of biodiversity, therefore, remain. Genetically altered plants, however, raise new (78) , such as the effects that they may have on us and the environment. "We are flying blindly into a new (79) of agricultural biotechnology with high hopes, few constraints, and little idea of the potential (80) " said science writer Jeremy Rifkin.
资产负债表和损益表都是反映企业特定日期财务状况的会计报表。（）
In recent years a new farming revolution has begun, one that involves the (61) of life at a fundamental level--the gene. The study of genetics has (62) a new industry called biotechnology. As the name suggests, It (63) biology and modern technology through such techniques as genetic engineering. Some of the new biotech companies specialize in agriculture and are working feverishly to (64) seeds that give a high yield, that (65) diseases, drought and frost, and that reduce the need for (66) chemicals. If such goals could be achieved, it would be most (67) . But some have raised concerns about genetically engineered crops. In nature, genetic diversity is created within certain (68) . A rose can be crossed with a different kind of rose, but a rose will never cross with a potato. Genetic engineering, (69) usually involves taking genes from one species and inserting them into another (70) to transfer a desired characteristic. This could mean, for example, selecting a gene which leads to the production of a chemical with anti-freeze (71) from an artic fish, and inserting it into a potato or strawberry to make it frost-resistant. (72) , then, biotechnology allows humans to (73) the genetic wails that separate species. Like the green revolution, (74) some call the gene revolution contributes to the problem of genetic uniformity--some say even more so (75) geneticists can employ techniques such as cloning and (76) culture (培养), processes that produce perfectly (77) copies. Concerns about the erosion of biodiversity, therefore, remain. Genetically altered plants, however, raise new (78) , such as the effects that they may have on us and the environment. "We are flying blindly into a new (79) of agricultural biotechnology with high hopes, few constraints, and little idea of the potential (80) " said science writer Jeremy Rifkin.
微信支付 
支付宝支付