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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 overfished 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 the 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.

　　31. The extinction of large prehistoric animals is noted to suggest that_____.

　　A. large animals were vulnerable to the changing environment.

　　B. small species survived as large animals disappeared.

　　C. large sea animals may face the same threat today.

　　D. Slow-growing fish outlive fast-growing ones

　　32. We can infer from Dr Myers and Dr. Worm’s paper that_____.

　　A. the stock of large predators in some old fisheries has reduced by 90%.

　　B. there are only half as many fisheries as there were 15 years ago.

　　C. the catch sizes in new fisheries are only 20% of the original amount.

　　D. the number of larger predators dropped faster in new fisheries than in the old.

　　33.By saying “these figures are conservative” (Line 1, paragraph 3), Dr Worm means that_____.

　　A. fishing technology has improved rapidly.

　　B. the catch-sizes are actually smaller then recorded.

　　C. the marine biomass has suffered a greater loss.

　　D. the data collected so far are out of date.

　　34. Dr Myers and other researchers hold that_____.

　　A. people should look for a baseline that can work for a longer time.

　　B. fisheries should keep the yield below 50% of the biomass

　　C. the ocean biomass should restored its original level.

　　D. people should adjust the fishing baseline to changing situations

　　35. The author seems to be mainly concerned with most fisheries’ _____.

　　A. management efficiency

　　B. biomass level

　　C. catch-size limits

　　D. technological application.
 

答案解析

　　文章解析：根据中心统一原则确定，

　　文章首段主题句是Now something similar could be happening in the oceans. 现在，类似现象(大型的生长缓慢的动物比较容易猎取，由于被捕猎而迅速灭绝)可能正在海洋中发生。

　　第二段确定段落内容方向的语句是That the seas are being overfished has been known for years. 人类发现鱼类过度捕捞已经有些年了。

　　第三段确定段落内容方向的语句是Dr Worm acknowledges that the figures are conservative. Worm博士声称这些数字比较保守。

　　第四段确定段落内容方向的语句是Dr Myers and Dr Worm argue that their work gives a correct baseline, which future management efforts must take into account. Myers博士和Worm博士指出，他们的工作确定了一个正确的基准，未来的海洋管理必须将其考虑在内。

　　不难发现，这篇文章围绕着海洋大型生物灭绝的问题来展开。

　　题目解析：

　　31. 结构题The extinction of large prehistoric animals is noted to suggest that_____.

　　选项A. large animals were vulnerable to the changing environment.

　　大型海洋动物面对环境变化很脆弱。

　　B. small species survived as large animals disappeared.

　　由于大型动物消失所以小型动物存活下来。

　　C. large sea animals may face the same threat today.

　　大型海洋动物可能面对相同的威胁。

　　D. Slow-growing fish outlive fast-growing ones

　　生长慢的鱼类生存时间比生长快的长。

　　该题将例子“The extinction of large prehistoric animal”定位到文章第一段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.” 例子从段落首句开始到倒数第二句结束。根据结构题方位论原则，找例子对应的论点句。因此，例子后面相邻的句子Now something similar could be happening in the oceans. “现在类似现象(大型动物灭绝)可能正在海洋中发生。”是论点。选项A. large animals were vulnerable to the changing environment.大型海洋动物面对环境变化很脆弱，与相关信息句动作“现在类似现象(大型动物灭绝)可能正在海洋中发生”没有任何关联;选项B. small species survived as large animals disappeared.由于大型动物消失所以小型动物存活下来，与相关信息句动作“现在类似现象(大型动物灭绝)可能正在海洋中发生”没有任何关联;选项C. large sea animals may face the same threat today.大型海洋动物可能面对相同的威胁，与相关信息句动作“现在类似现象(大型动物灭绝)可能正在海洋中发生”直接关联，动作“大型海洋动物面对相同的威胁”对应于“类似现象可能正在海洋中发生”，体现“同意替换”的关系;选项D. Slow-growing fish outlive fast-growing ones.生长慢的鱼类生存时间比生长快的长，与相关信息句动作““现在类似现象(大型动物灭绝)可能正在海洋中发生”没有任何关联。因此，正确答案为C. large sea animals may face the same threat today. 大型海洋动物可能面对相同的威胁。

　　32. 细节题We can infer from Dr Myers and Dr. Worm’s paper that_____.

　　选项A. the stock of large predators in some old fisheries has reduced by 90%.

　　有些老渔场大型动物的存活量已经减少了90%。

　　B. there are only half as many fisheries as there were 15 years ago.

　　现在渔场的数量是15年前的一半

　　C. the catch sizes in new fisheries are only 20% of the original amount.

　　新渔场中的捕鱼量只占雨总量的20%。

　　D. the number of larger predators dropped faster in new fisheries than in the old.

　　新的渔场中大型食肉类的数量比旧渔场下降的快。

　　该题利用定位词“Dr Myers and Dr. Worm’s paper”粗略定位到文章第二段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.利用“paper”准确定位到段落的句子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.“根据他们最近发表在《自然》中的论文，一个新的渔场中大型食肉鱼类的数量在开始开发海洋资源的15年间平均下降了80%，在一些旧的渔场，这15年来，大型食肉鱼类的数量在此基础上又减少了一半。”因此，正确答案为A. the stock of large predators in some old fisheries has reduced by 90%. 有些老渔场大型动物的存活量已经减少了90%。

33.识词题By saying “these figures are conservative” (Line 1, paragraph 3), Dr Worm means that_____.

　　选项A. fishing technology has improved rapidly.

　　捕鱼技术发展很迅速。

　　B. the catch-sizes are actually smaller then recorded.

　　实际上捕鱼量比记录的要少。

　　C. the marine biomass has suffered a greater loss.

　　海洋生物群遭受了严重的损失。

　　D. the data collected so far are out of date.

　　目前收集的数据过时了。

　　该题将识别的短语“these figures are conservative”在文章中定位到第三段Dr Worm acknowledges that the 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. 作为识词题，按照“方位论原则”：在识别词汇后面找表示“解释说明，逻辑关系”的表达，或者向前面找平行结构。在词汇后面出现“That means”，表示解释说明关系相关信息句为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. “这意味着更多的海洋生物被捕获，因此现在和过去的渔业情况的真实差距可能比记录下来的捕获量的变化还要大。” 选项A. fishing technology has improved rapidly. 捕鱼技术发展很迅速，与相关信息句动作“意味着更多的海洋生物被捕获，因此现在和过去的渔业情况的真实差距可能比记录下来的捕获量的变化还要大”没有任何关联;选项B. the catch-sizes are actually smaller then recorded. 实际上捕鱼量比记录的要少，与相关信息句动作“意味着更多的海洋生物被捕获，因此现在和过去的渔业情况的真实差距可能比记录下来的捕获量的变化还要大”恰恰相反;选项C. the marine biomass has suffered a greater loss.海洋生物群遭受了严重的损失，与相关信息句动作“意味着更多的海洋生物被捕获，因此现在和过去的渔业情况的真实差距可能比记录下来的捕获量的变化还要大”没有任何关联;选项D. the data collected so far are out of date.目前收集的数据过时了，与相关信息句动作“意味着更多的海洋生物被捕获，因此现在和过去的渔业情况的真实差距可能比记录下来的捕获量的变化还要大”直接关联，动作“目前收集的数据过时了”对应于“现在和过去的渔业情况的真实差距可能比记录下来的捕获量的变化还要大”。因此，答案应选D. the data collected so far are out of date. 目前收集的数据过时了。

　　34. 细节题Dr Myers and other researchers hold that_____.

　　选项A. people should look for a baseline that can work for a longer time.

　　人们应该寻找一个能适用较长时间的基准。

　　B. fisheries should keep the yield below 50% of the biomass.

　　渔场应该将捕鱼量控制在存活量的50%以下。

　　C. the ocean biomass should restored its original level.

　　海洋生物群落应该恢复到原来的水平。

　　D. people should adjust the fishing baseline to changing situations.

　　人们应该调整捕鱼的基准以适应时时变化的条件。

　　该题利用定位词“Dr Myers and other researchers”定位到文章第四段Dr Myers and Dr Worm argue that their work gives a correct baseline, which future management efforts must take into account. “Myers博士和Worm博士指出，他们的工作确定了一个正确的基准，未来的海洋管理必须将其考虑在内。” 选项A. people should look for a baseline that can work for a longer time.人们应该寻找一个能适用较长时间的基准，与文中定位语句的动作“确定了一个正确的基准，未来的海洋管理必须将其考虑在内”没有任何关联;选项B. fisheries should keep the yield below 50% of the biomass.渔场应该将捕鱼量控制在存活量的50%以下，与文中定位语句的动作“确定了一个正确的基准，未来的海洋管理必须将其考虑在内”没有任何关联;选项C. the ocean biomass should restored its original level.海洋生物群落应该恢复到原来的水平，与文中定位语句的动作“确定了一个正确的基准，未来的海洋管理必须将其考虑在内”没有任何关联;选项D. people should adjust the fishing baseline to changing situations.人们应该调整捕鱼的基准以适应时时变化的条件，与文中定位语句的动作“确定了一个正确的基准，未来的海洋管理必须将其考虑在内”没有任何关联。可见，定位词定位的语句不能确定唯一正确的答案。作为细节题，要向下一句一句逐一与选项比较，知道最终确定答案。后面语句叙述到 They believe the data support an idea current among marine biologists, that of the "shifting baseline". “他们相信这些数据能够支持目前海洋生物学家认可的观点：改变基准。” 选项A. people should look for a baseline that can work for a longer time.人们应该寻找一个能适用较长时间的基准，与相关信息句动作“相信这些数据能够支持目前海洋生物学家认可的观点：改变基准”没有直接关联;选项B. fisheries should keep the yield below 50% of the biomass.渔场应该将捕鱼量控制在存活量的50%以下，与相关信息句动作“相信这些数据能够支持目前海洋生物学家认可的观点：改变基准”没有任何关联;选项C. the ocean biomass should restored its original level.海洋生物群落应该恢复到原来的水平，与相关信息句动作“相信这些数据能够支持目前海洋生物学家认可的观点：改变基准”没有直接关联;选项D. people should adjust the fishing baseline to changing situations.人们应该调整捕鱼的基准以适应时时变化的条件，与相关信息句动作“相信这些数据能够支持目前海洋生物学家认可的观点：改变基准”直接关联，动作“调整捕鱼基准适应变化的条件”对应于“改变基准”，体现“同意替换”的关系。因此，正确答案为D. people should adjust the fishing baseline to changing situations. 人们应该调整捕鱼的基准以适应时时变化的条件。

　　35. 细节题The author seems to be mainly concerned with most fisheries’ _____.

　　选项A. management efficiency 管理效率

　　B. biomass level 生物群落水平

　　C. catch-size limits 捕量限制

　　D. technological application 技术应用

　　该题利用定位词“mainly”粗略定位到文章第四段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. “这很重要，因为理论表明当这一目标物种生物群落的数量是原来的50%时，人们能够从渔业得到的最大的可持续性的产出。但大多数渔场的数量低于50%这种做生意的方式很糟糕。”显然，生物群落的数量和水平决定了从事该行业人的收入。因此，正确答案为B. biomass level 生物群落水平。

　　全文翻译当史前人类来到地球新的地域时，大型动物发生了一些奇怪的事情，他们突然之间灭绝了，小一点儿的物种得以存活。那些大型的、生长缓慢的动物比较容易猎取，由于被猎杀而迅速灭绝。现在类似的情况可能正在海洋中发生。

　　人们知道海洋中的鱼类过量捕捞已经有些年了。Ransom Myers和Boris worm这些研究人员只是让我们知道了事情变化得多快。他们查询了来自世界各地渔场的50年的数据，目的并非去估算在海洋中的某些特定部分的鱼类的实际数量，而是不同时间内鱼类数量的改变。根据他们发表在《自然》期刊上的最新论文，一个新的渔场中的大型食肉鱼渔类的数量在开始开发海洋资源的15年间平均下降了80%，在一些旧的渔场，这15年来，大型食肉鱼类的数量在此基础上又减少了一半。

　　Worm博士生成这些数字比较保守。一个原因是捕鱼技术有所改进。如今，船只可以借助卫星和声纳定位仪发现猎物，这在50年前无法作到。这意味着更多的海洋生物被捕获，因此现在和过去渔业情况的真实差距可能比记录下来的捕获量的变化还要大。此外，在早些年，多钩长线上可能会挂满更多的鱼，但是因为没有挂了鱼饵的鱼钩来诱惑它们了，所以一些鱼就没被捕到，这就造成了对过去海洋中的鱼类数量估计不足。而且，在早期用多钩长线钓鱼时，许多鱼在上钩后被鲨鱼吃掉了。现在这不成问题了，因为现在鲨鱼数量少了。

　　Myers博士和Worm博士指出，他们的工作确定了一个正确的基准，未来的(海洋)管理必须将其考虑进去。他们相信这些数据能够支持目前海洋生物学家认可的观点：改变基准。这一观点指出人们没有察觉发生在海洋中的巨大变化是因为他们在审视与现在做对比的过去时，用来衡量这个变化的时间段相对较短。这很重要，因为理论表明当某一目标物种的数量是原来的50%时，人们能够从渔业得到最大的可持续性的产出。但大多数渔场的数量低于原来的50%，这种做生意方式很糟糕。