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 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。
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 yields below 50% of the biomass。
[C] the ocean biomass should be restored to its original level。
[D] people should adjust the fishing baseline to the 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。
名師解析
31. The extinction of large prehistoric animals is noted to suggest that
提及大型史前動(dòng)物的滅絕是為了說明
[A] large animals were vulnerable to the changing environment。
大型動(dòng)物容易受到環(huán)境變化的影響。
[B] small species survived as large animals disappeared。
當(dāng)大型動(dòng)物消失的時(shí)候小型物種存活了下來。
[C] large sea animals may face the same threat today。
大型海洋動(dòng)物今天面臨相同的威脅。
[D] slow-growing fish outlive fast-growing ones。
成長(zhǎng)緩慢的魚要比成長(zhǎng)快速的魚活得長(zhǎng)。
【答案】 C
【考點(diǎn)】 推斷題。
【分析】 通過題干關(guān)鍵詞“大型史前動(dòng)物的滅絕”可以定位到第一段。作者提到它們的滅絕是由于人類的捕殺，作者在第一段比較后一句提到，“如今類似的事情可能會(huì)發(fā)生在海洋中”。因此可以得出結(jié)論，即，作者是為了引用大型史前動(dòng)物的滅絕來引出海洋物種同樣面臨著由于人類過度捕撈而滅絕的這個(gè)話題，故正確答案是[C]。[A]、[B]、[D]選項(xiàng)都沒有能夠表達(dá)出作者的這個(gè)意圖，而只是很淺層去分析表象。
32. We can infer from Dr. Myers and Dr. Worm’s paper that
從邁爾斯博士和沃爾姆博士的論文中我們可以推斷出
[A] the stock of large predators in some old fisheries has reduced by 90%。
一些老漁場(chǎng)里大型捕食類魚種的貯存量已經(jīng)減少了90%。
[B] there are only half as many fisheries as there were 15 years ago。
現(xiàn)在漁場(chǎng)的數(shù)量只有15年前數(shù)量的一半。
[C] the catch sizes in new fisheries are only 20% of the original amount。
新的漁場(chǎng)中的捕捉數(shù)量是原來數(shù)量的20%。
[D] the number of larger predators dropped faster in new fisheries than in the old。
新的漁場(chǎng)里大型捕食類魚種的數(shù)目下降比舊的漁場(chǎng)快。
【答案】 A
【考點(diǎn)】 推斷題。
【分析】 根據(jù)題干關(guān)鍵詞“Dr Myers and Dr. Worm’s paper”可以定位到第二段比較后一句，“根據(jù)他們發(fā)表在《自然》雜志上的比較新論文，一個(gè)新的漁場(chǎng)在被開發(fā)后的15年中大型捕食類魚種的生物量平均減少了80%。在有些長(zhǎng)期捕撈的地區(qū)，自那以后，這個(gè)數(shù)量又減少了一半。”本句的理解難點(diǎn)就是“In some long-fished areas, it has halved again since then。”這句話里面的“since”從什么時(shí)間開始計(jì)算，影響本題的解答�！皊ince”指的是從15年結(jié)束后開始算呢，還是從15年的第一年開始算。如果是前者，則答案是[A]，因?yàn)樾碌钠骄陆?0%，然后又下降了一半，這個(gè)意思就是一共下降了90%；如果是后者，則得出舊漁場(chǎng)大型捕食類魚種的減少速度低于新漁場(chǎng)，而且只有50%。“since”接時(shí)間，后面必須是一個(gè)時(shí)間點(diǎn)。如果“since”后面接的不是一個(gè)時(shí)間點(diǎn)而是時(shí)間段，則從該時(shí)間段結(jié)束的時(shí)候開始算。例句：“It has been 10 years since I lived in Beijing�！边@句話的意思不是“我在北京十年了”，而是“我離開北京十年了”。因此本題的正確答案是[A]�！皊ince”接的是15年結(jié)束后的那個(gè)點(diǎn)；而且這句話里面還有一個(gè)很關(guān)鍵的詞“again”(再次)，也很明顯說明這里指的是“在下降80%之后，又再次減少了一半”，即“余下的20%又減少了一半，只剩下10%”。
33. By saying“these figures are conservative”(Line 1, Paragraph 3)， Dr worm means that
沃爾姆博士說“these figures are conservative”(第三段第一行)，他的意思是
[A] fishing technology has improved rapidly. 捕魚的技術(shù)已經(jīng)得到快速提高。
[B] the catch-sizes are actually smaller than recorded. 捕魚量比實(shí)際記錄的少。
[C] the marine biomass has suffered a greater loss. 海洋生物量已經(jīng)蒙受了更大的損失。
[D] the data collected so far are out of date. 目前收集的數(shù)據(jù)已經(jīng)過時(shí)了。
【答案】 C
【考點(diǎn)】 推斷題。
【分析】 根據(jù)關(guān)鍵詞“conservative”的提示定位到第三段第一句。作者說“這個(gè)數(shù)據(jù)是保守的，因?yàn)椴遏~的技術(shù)已經(jīng)提高了。衛(wèi)星和聲納定位儀都用上了。這就意味著現(xiàn)在海里有更高比例的海洋生物被捕撈了�，F(xiàn)在和過去的真正差異可能比通過捕撈記錄的反映出來的差異更要糟糕�！苯酉聛淼囊痪湓挼囊馑际恰耙郧耙恍┳ゲ蛔〉暮Ｑ笊铿F(xiàn)在都可以抓住了，以前被鯊魚搶走的，現(xiàn)在由于鯊魚都不見了，自然被捕撈的就更多了�！弊髡咄瑫r(shí)提到，“由于以前的捕撈技術(shù)不夠先進(jìn)，所以以前對(duì)海里的生物的總量是低估的。”那么我們可以得出這樣的結(jié)論“以前的海洋生物總量比我們當(dāng)時(shí)估計(jì)的要高，而現(xiàn)在只剩下這么一點(diǎn)了”，就是說“海洋物種被捕撈的比例遠(yuǎn)遠(yuǎn)超過我們的記錄”。因此可以得出[C]的結(jié)論。[A]項(xiàng)的錯(cuò)誤在于“捕魚的技術(shù)已經(jīng)得到快速的提高”這種提法僅僅是作者文中提到的一個(gè)原因，作者是為了用這個(gè)來證明有了這樣的科技，更多的海洋生物就被捕撈了，而不是為了說明技術(shù)得到提高。[B]試圖比較當(dāng)時(shí)的捕撈量與記錄的差別。但是原文說的是今天和過去的真實(shí)差別比那個(gè)記錄反映出來的差別要嚴(yán)重的多。[D]的說法是沒有根據(jù)的。
34. Dr. Myers and other researchers hold that
邁爾斯博士以及其他一些研究人員堅(jiān)持認(rèn)為
[A] people should look for a baseline that can work for a longer time。
人們應(yīng)該尋找一種能夠更長(zhǎng)時(shí)間起作用的基準(zhǔn)。
[B] fisheries should keep the yields below 50% of the biomass。
漁場(chǎng)應(yīng)該將產(chǎn)量保持在生物量的50%以下。
[C] the ocean biomass should be restored to its original level。
海洋生物的數(shù)量應(yīng)該恢復(fù)到原來的水平。
[D] people should adjust the fishing baseline to the changing situation。
人們應(yīng)該根據(jù)變化的形勢(shì)調(diào)整捕魚數(shù)量的基準(zhǔn)。
【答案】 D
【考點(diǎn)】 事實(shí)細(xì)節(jié)題。
【分析】 本題提到“Dr. Myers”和其他一些研究者的主張，題干中用到了“hold”，而其近義詞就是“argue”，定位到比較后一段第一句�！癉r. Myers”和“Dr. Worm”堅(jiān)持認(rèn)為“他們的工作是給出準(zhǔn)確的捕撈數(shù)量基準(zhǔn)，它是未來的管理工作必定要考慮的”，他們相信自己的數(shù)據(jù)支持了目前海洋生物學(xué)家的觀點(diǎn)，即“變化的底線”。也就是說，“人們應(yīng)該根據(jù)變化的形勢(shì)調(diào)整捕魚數(shù)量的基準(zhǔn)”，所以正確答案是[D]。[A]不正確的原因是文章中沒有提到持續(xù)時(shí)間更長(zhǎng)，文章比較后一段提到時(shí)間太短指的是調(diào)查研究的跨度年份很短。和基數(shù)沒有關(guān)系 [B]不是“Dr. Myers”堅(jiān)持的主張，而是理論狀態(tài)下的海洋生物生產(chǎn)。[C]與原文的意思也不符合。
35. The author seems to be mainly concerned with most fisheries’
作者看上去主要關(guān)注大多數(shù)漁場(chǎng)的
[A] management efficiency. 經(jīng)營(yíng)效率。
[B] biomass level. 生物量水平。
[C] catch-size limits. 捕撈量的限制。
[D] technological application. 技術(shù)應(yīng)用。
【答案】 B
【考點(diǎn)】 文章主旨題。
【分析】 本題問的是作者比較關(guān)注的是漁場(chǎng)的哪一個(gè)方面，這個(gè)問題實(shí)際上考的是文章的主旨。從前到后，作者一直在提過度捕撈對(duì)海洋生物量的影響。[A]顯然不是本文的重點(diǎn)。[D]在文章中只是被作者引用來表示現(xiàn)在的海洋生物被過度捕撈。[C]在文中比較后一段有提及，但是顯然不是文章的主題。作者比較關(guān)心的是海洋生物量的變化，因此正確答案選[B]項(xiàng)。
難句解析：
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。
【結(jié)構(gòu)分析】 本句是一個(gè)并列句，連接詞是“so”。前一個(gè)分句中，“that means” 后面省略了賓語從句連接詞“that”，在這個(gè)賓語從句中，“a higher proportion of what is in the sea”是主語，“is being caught”是謂語部分。這個(gè)主語里面又包含了一個(gè)由“what”引導(dǎo)的從句，做介詞“of”的賓語。后一個(gè)分句是一個(gè)比較級(jí)結(jié)構(gòu)，主語是“the real difference”，“the one”代替“the difference”，“recorded”是過去分詞做后置定語。
2. 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。
【結(jié)構(gòu)分析】 這里是兩個(gè)句子。之所以把第一句拿來一起分析，是因?yàn)檫@句話的理解對(duì)第二句的理解很重要。第一句話中的“would have been more saturated”是虛擬語氣的一種，是對(duì)過去未能發(fā)生的事情的一種假設(shè)。隨后一句，仍然是虛擬語氣。我們來分析一下這個(gè)結(jié)構(gòu)�！皊ince”指的是原因，即，“當(dāng)時(shí)怎么就沒有這樣的可以裝誘餌的魚鉤”，其實(shí)際意思是“如果當(dāng)初有這樣的魚鉤，一些海洋生物個(gè)體就不會(huì)被抓不住”�！發(fā)eading”是現(xiàn)在分詞引導(dǎo)結(jié)果狀語。
3. 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。
【結(jié)構(gòu)分析】 本句的主句是“The notion is that…”，“that”引導(dǎo)表語從句。在這個(gè)表語從句中，“people have failed to detect the massive changes”是句子的主謂賓，“which”引導(dǎo)一個(gè)定語從句，指代“changes”。“because”引導(dǎo)一個(gè)原因狀語從句，在表語從句中表示原因。
4. 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。
【結(jié)構(gòu)分析】 本句的主句是“that matters”，“because”引導(dǎo)一個(gè)原因狀語從句。在這個(gè)從句中，“theory suggests”是主句，“suggest”后面的“that”引導(dǎo)一個(gè)賓語從句。
全文翻譯：
當(dāng)史前人類來到世界的各個(gè)新區(qū)域時(shí)，一些奇怪的事情也會(huì)發(fā)生在當(dāng)?shù)氐拇笮蛣?dòng)物身上。它們突然就滅絕了，較小的物種存活了下來。生長(zhǎng)緩慢的大型的動(dòng)物很容易成為獵物，很快被獵殺而滅絕�，F(xiàn)在類似的情形也可能正在海洋中發(fā)生。
人們知道海洋被過度捕撈這個(gè)事實(shí)已經(jīng)很多年了。邁爾斯博士和沃爾姆博士這樣的研究人員所展示的情況說明了變化有多快。他們研究了全世界漁場(chǎng)半個(gè)世紀(jì)的數(shù)據(jù)。他們的方法不是試圖確切估計(jì)在具體某地方的海洋中魚類的量，而是估計(jì)該地區(qū)生物量隨著時(shí)間推移的變化。根據(jù)他們發(fā)表在《自然》雜志上的比較新論文，一個(gè)新的漁場(chǎng)在被開發(fā)后的頭15年中大型捕食類魚種的生物量平均減少了80%。在有些長(zhǎng)期捕撈的地區(qū)這個(gè)數(shù)量隨后又減少了一半。
沃爾姆博士承認(rèn)這些數(shù)據(jù)是保守的。其中一個(gè)原因是捕魚技術(shù)已經(jīng)得到發(fā)展，今天的船只可以使用衛(wèi)星和聲納定位儀來尋找獵物，這些在50年前都還沒有。這意味著更高比例的海洋生物正在被捕撈，因此現(xiàn)在和過去的真正差異可能比捕撈量記錄反映的差異更要糟糕。以前，多鉤長(zhǎng)線本可以抓更多的魚，但是因?yàn)楫?dāng)時(shí)沒有可用來捕捉它們的帶魚餌的鉤，個(gè)別的魚在當(dāng)時(shí)就沒有被捉住，這導(dǎo)致了過去對(duì)魚的貯存量的低估。而且，在用多鉤長(zhǎng)線捕撈的初期，許多魚被鉤住后又被鯊魚奪走。而現(xiàn)在這不再是問題，因?yàn)楦浇孽忯~更少了。
邁爾斯博士和沃爾姆博士認(rèn)為他們的工作給出了準(zhǔn)確的捕撈數(shù)量基準(zhǔn)，它是未來的管理工作必須要考慮在內(nèi)的。他們認(rèn)為這些數(shù)據(jù)支持了現(xiàn)在海洋學(xué)家的一種觀點(diǎn)，即“變化的底線”。這種觀點(diǎn)認(rèn)為人們沒有檢測(cè)出海洋中已經(jīng)發(fā)生的巨大變化，因?yàn)樗麄冎换仡櫫诉^去相當(dāng)短的一段時(shí)期。這有很大的影響，因?yàn)槔碚擄@示，漁場(chǎng)中要獲得比較大可持續(xù)產(chǎn)量，目標(biāo)物種的生物量需要維持在原來水平的約50%。但是大部分漁場(chǎng)低于這個(gè)水平，這可不是好的商業(yè)做法。
