2009考研英语三层递进攻克阅读理解(11)

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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.
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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 animal 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］ then 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't 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 situation.
35. The author seems to be mainly concerned with most fisheries'.
［A］ management efficiency
［B］ biomass level
［C］ catch size limits
［D］ technological application.

kyfive

核心词汇：

bait n.饵，引诱物vt.用饵引诱；折磨，奚落
baseline n. 基准线，基础，起点，准则；（据通货膨胀率作出调整的）政府开支基数
biomass n. 生物量
conservative a.保守的,守旧的n.保守主义者（conserve+ative形容词后缀→保守的）
crop n.作物,庄稼;一批,大量
current n.电流,水流;潮流,趋势a.当前的;流通的（curr+ent形容词后缀→跑的→流动的）
detect v.察觉,发觉,侦察,探测（de打开+tect把盖上的打开,发觉）
estimate v./n.估计,估价;评估
exploit v.开拓;开发;剥削n.功绩［勋］;业绩（ex出+ploit→探索出→开拓）；
exploitation n. 开发，开拓，剥削
extinct a.灭绝的;熄灭了的（ex出+（s）tinct→刺出来→灭绝的）
halve vt. 减半，平分
marine a.海的,海生的;船舶的,航海的（marin+e形容词后缀）
massive a.大而重的,厚实的,粗大的;大规模的,大量的（mass+ive形容词后缀）
predator n.掠夺者，捕食其他动物的动物
prehistory n. 史前时期（pre+history历史）；
prehistoric a. 史前的
prey n.被掠食者,牺牲者,掠食v.捕食,掠夺,折磨
saturate vt.使湿透，浸透；使充满，使饱和（satur+ate动词后缀→使足够→饱和）
species n.物种; 种（speci外观，种类+es→种类，物种）
stock n.种类，备料,库存,现货;股票,公债v.储存
sustain vt.支撑,撑住;维持,持续,经受,忍耐（sus下面+tain→在下面拿住→支持）;
sustainable a. 能承受的，能维持的，可持续的；（经济上）保持在一定水平上的；能保持一定发展速度的
target n.目标,对象,靶子
trap n.陷阱，圈套vt.诱捕vi.设圈套
yield v.出产,生长;(to)屈服,服从n.产量,收获
难句分析：
难句1
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.
［分析］此句是一个主从复合句，从句在前，主句在后；从句的主语是that，谓语是means，宾语由从句a higher proportion...is being caught充当，其中主语a higher proportion 带有介词of+从句what is in the sea 作定语。
［译文］这就意味着海洋生物被捕捞的比例大大提高了，所以现在和过去之间的捕获量之间的实际差别要比记录变化所反映的要更糟。
难句2
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.
［分析］此句是一个复合句，主句在前，从句在后，由since引导，表示原因，而句末的现在分词结构leading to an underestimate...作状语。
［译文］因此，因为没有多余的挂着诱饵的钩子的诱捕，个别的鱼可能没有被钓到，这就使得过去的鱼类储量被低估。
难句3
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.
［分析］此句主干是"That matters...",句中 because引导一个原因状语从句because theory suggests...；后面的that引导一个宾语从句that the maximum sustainable yield...comes (yield后面又带有一个that 引导的定语从句that can be cropped from a fishery)，其中又含有状语从句when the biomass of a target species is about 50% of its original levels.
［译文］这点之所以很重要是因为理论指出，一个渔场若能够获得最高持续产量，只有当目标物种的生物量是原来水平的50%时才能实现。

kytwo

文章类型：自然科学--海洋鱼类的过度捕捞
文章通过海洋大型动物正在灭绝这一事实，说明人们可以根据时间变化调整鱼类存量基线，从而做到不过度捕捞。
答案详解：
31. 文中提到大型史前动物的灭绝是为了说明：
［A］ 大型动物容易受到变化的环境的影响。
［B］ 由于大型动物的消失，小型物种得以存活。
［C］ 当今的大型海洋运动可能面临同样的威胁。
［D］ 生长缓慢的鱼类比生长迅速的鱼类活得久。
细节事实题【正确答案】［C］
根据第一段的末句"Now something similar could be happening in the oceans."现在，类似的情景可能就发生在海洋之中，可以判断［C］项正确。
32. 根据迈斯博士和沃姆博士的研究报告，我们可以推知：
［A］ 在一些老渔场，大型捕食动物的存量已经减少了90%。
［B］ 现在的渔场的数量只有15年前的一半。
［C］ 新渔场捕获物的大小只有原先的20%。
［D］ 新渔场较大捕食动物的数量下降的速度比老渔场快。
推理题【正确答案】［A］
这道题关键是要理解原文第二段的最后一句, ...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 longfished areas, it has halved again since then.前一个句子讲大型食肉动物减少了80%, 即剩下20%，现在，在一些长期捕鱼的地区，其总量又减少了一半。所以总共减少了90%。
33. 通过说"这些是保守的数字"（第三段，第1行），沃姆博士的意思是
［A］ 捕鱼技术有了提高。
［B］ 捕获物的大小实际上比记载的小。
［C］ 海洋生物的数量大量减少。
［D］ 到目前为止，收集的数据过时了。
句子理解题【正确答案】［C］
整篇文章的主题是海洋鱼类需要保护。文章第二段提到的数字只是一种保守数字，因为没有考虑到如今捕鱼科技进步造成的鱼类数量减少，暗含的意思是鱼类资源遭受的损失要更加严重。所以选择［C］项。
34. 迈耶斯博士和其他研究人员认为
［A］ 人们应当寻找一个不能在较长时间里有效的基准。
［B］ 渔场应将捕获量维持在海洋生物数量的50%以下。
［C］ 海洋生物数量应当恢复到原先的水平。
［D］ 人们应当根据变化的情况调节基准。
细节事实题【正确答案】［D］
文章最后一段提到给出一个correct baseline 才行，就是要调整原来的baseline。文中的"shifting baseline"也提示了答案。所以选择［D］项。
35. 作者似乎主要关注大多数渔场的
［A］ 管理效率。
［B］ 生物数量水平。
［C］ 捕获物大小的限制。
［D］ 科技应用
中心主旨题【正确答案】［B］
本文的主题是渔业的过度捕捞，而文章主要引用的是麦尔斯和沃姆博士的研究成果，即经过长时间的观察，发现单位海域内海洋生物总量下降速率，并提出维持渔业可持续发展的baseline（捕捞基准线）。由此可见，本文作者关注的焦点及测算的依据主要是单位海域内的海洋生物总量。所以选择［B］项。

kysix

全文精译：
史前人类踏上新大陆时，大型动物横遭不测：它们突然灭绝了，而小型的物种存活了下来。大型的、生长缓慢的动物就成了易于捕获的猎物，很快被捕杀以至灭绝。现在，类似的情景可能就发生在海洋之中。
第一段：大型史前动物比小型动物灭亡的快的现象与原因。
多年来，我们就已经知道，海洋正在被过度捕捞。研究者如伦森·麦尔斯和鲍里斯·沃姆所告诉我们的发现只是说明形势正在恶化到什么程度。他们研究了全世界半个世纪的捕鱼资料，它们的方法并非试图估算大海中某个特定区域的鱼类单位面积内的生物量（活体生物数量），而是为了揭示生物数量在一段时间内的变化情况。根据他们在《自然》杂志上最新发表的论文，一个新渔场的大型食肉动物（捕食其他队伍的动物）的生物量在开始经营的十五年内平均减少80%；在一些长期捕鱼的地区，其总量又减少了一半。
第二段：伦森·麦尔斯和鲍里斯·沃姆博士给出对海洋生物群落随时间变化的研究成果。
沃姆博士承认，这些数字过于保守，原因之一是因为捕鱼技术的提高。如今，渔船可以通过卫星和声呐找到鱼群，而这些技术在50年前是没有的。这就意味着海洋生物被捕捞的比例大大提高了，所以现在和过去捕获量之间的实际差别要比记录变化所反映的要更糟。在早期，就是用多钩长线捕鱼都应该钓到更多的鱼。因此，因为没有多余的挂着诱饵的钩子的诱捕，个别的鱼可能没有被钓到，这就使得过去的鱼类储量被低估。再者，在多钩长线钓鱼的早期，许多鱼在上钩后都成为鲨鱼的食物。现在这已经不再成为问题，因为没有多少鲨鱼出没。
第三段：两位博士的统计数字是保守的及其原因。
麦尔斯和沃姆博士坚持认为，它们的研究为捕捞划了一条正确的基线，未来的管理决策者必须给予重视。他们相信这些资料支持目前在海洋生物学家中流行的一种观点，就是"动态捕捞基线"的观点，这种观点认为因为人们只限于对过去相对较短的时期的研究，所以他们没有能够觉察到大海中所发生的巨大变化。这点之所以很重要是因为理论指出，一个渔场若能够获得最高持续产量，只有当目标物种的生物量是原来水平的50%时才能实现，而大部分的渔场都处于这个水平之下，这样的生财之道是很不利的。
第四段：两位博士的结论及多数海洋学家的观点。