閱讀建議:
1) 北京新東方建議讀者先按自己的節(jié)奏閱讀文章并做完題目,再看文章分析及題目講解。
文章及題目:
A recent study has provided clues to predator-prey dynamics in the late Pleistocene era. Researchers compared the number of tooth fractures in present-day carnivores with tooth fractures in carnivores that lived 36,000 to 10,000 years ago and that were preserved in the Rancho La Brea tar pits in Los Angeles. The breakage frequencies in the extinct species were strikingly higher than those in the present-day species.
In considering possible explanations for this finding, the researchers dismissed demographic bias because older individuals were not overrepresented in the fossil samples. They rejected preservational bias because a total absence of breakage in two extinct species demonstrated that the fractures were not the result of abrasion within the pits. They ruled out local bias because breakage data obtained from other Pleistocene sites were similar to the La Brea data. The explanation they consider most plausible is behavioral differences between extinct and present-day carnivores-in particular, more contact between the teeth of predators and the bones of prey due to more thorough consumption of carcasses by the extinct species. Such thorough carcass consumption implies to the researchers either that prey availability was low, at least seasonally, or that there was intense competition over kills and a high rate of carcass theft due to relatively high predator densities.
1. The primary purpose of the passage is to
(A) present several explanations for a well-known fact
(B) suggest alternative methods for resolving a debate
(C) argue in favor of a controversial theory
(D) question the methodology used in a study
(E) discuss the implications of a research finding
2. According to the passage, compared with Pleistocene carnivores in other areas, Pleistocene carnivores in the La Brea area
(A) included the same species, in approximately the same proportions
(B) had a similar frequency of tooth fractures
(C) populated the La Brea area more densely
(D) consumed their prey more thoroughly
(E) found it harder to obtain sufficient prey
3. According to the passage, the researchers believe that the high frequency of tooth breakage in carnivores found at La Brea was caused primarily by
(A) the aging process in individual carnivores
(B) contact between the fossils in the pits
(C) poor preservation of the fossils after they were removed from the pits
(D) the impact of carnivores' teeth against the bones of their prey
(E) the impact of carnivores' teeth against the bones of other carnivores during fights over kills
4. The researchers' conclusion concerning the absence of demographic bias would be most seriously undermined if it were found that
(A) the older an individual carnivore is, the more likely it is to have a large number of tooth fractures
(B) the average age at death of a present-day carnivore is greater than was the average age at death of a Pleistocene carnivore
(C)in Pleistocene carnivore species, older individuals consumed carcasses as thoroughly as did younger individuals
(D) the methods used to determine animals' ages in fossil samples tend to misidentify many older individuals as younger individuals
(E) data concerning the ages of fossil samples cannot provide reliable information about behavioral differences between extinct carnivores and present-day carnivores
5. According to the passage, if the researchers had NOT found that two extinct carnivore species were free of tooth breakage, the researchers would have concluded that
(A) the difference in breakage frequencies could have been the result of damage to the fossil remains in the La Brea pits
(B) the fossils in other Pleistocene sites could have higher breakage frequencies than do the fossils in the La Brea pits
(C) Pleistocene carnivore species probably behaved very similarly to one another with respect to consumption of carcasses
(D) all Pleistocene carnivore species differed behaviorally from present-day carnivore species
(E) predator densities during the Pleistocene era were extremely high
1. 文章初讀:(只讀各段首句)
第一段首句:
A recent study has provided clues to predator-prey dynamics in the late Pleistocene era.
翻譯:一項(xiàng)最近的研究為更新世晚期的捕食者-獵物動(dòng)力學(xué)提供了線索。
評(píng):給出了文章的大背景,研究提供了關(guān)于P時(shí)代晚期捕食者-獵物動(dòng)力學(xué)的線索。所謂捕食者-獵物動(dòng)力學(xué),是研究捕食者數(shù)量和獵物數(shù)量的動(dòng)態(tài)聯(lián)系的,爭(zhēng)取用數(shù)學(xué)模型來描述和解釋兩者之間的動(dòng)態(tài)關(guān)系。
第二段首句:
In considering possible explanations for this finding, the researchers dismissed demographic bias because older individuals were not overrepresented in the fossil samples.
翻譯:在考慮這個(gè)發(fā)現(xiàn)的可能解釋時(shí),研究者對(duì)人口統(tǒng)計(jì)學(xué)錯(cuò)誤不予理會(huì),因?yàn)樵诨瘶颖局校ㄊ褂玫模└系膫(gè)體(樣本)并未超過適當(dāng)比例。
評(píng):關(guān)鍵詞possible explanations for this finding,點(diǎn)出了本段的的作用是探討對(duì)上段提到的發(fā)現(xiàn)的各種可能的解釋;究梢耘袛酁榻忉屝臀恼。
2. 文章精讀(精讀各句,把握邏輯關(guān)系)
第一段:(標(biāo)記重要邏輯關(guān)系詞及態(tài)度評(píng)價(jià)詞)
A recent study has provided clues to predator-prey dynamics in the late Pleistocene era. Researchers compared the number of tooth fractures in present-day carnivores with tooth fractures in carnivores that lived 36,000 to 10,000 years ago and that were preserved in the Rancho La Brea tar pits in Los Angeles. The breakage frequencies in the extinct species were strikingly higher than those in the present-day species.
In considering possible explanations for this finding, the researchers dismissed demographic bias because older individuals were not overrepresented in the fossil samples. They rejected preservational bias because a total absence of breakage in two extinct species demonstrated that the fractures were not the result of abrasion within the pits. They ruled out local bias because breakage data obtained from other Pleistocene sites were similar to the La Brea data. The explanation they consider most plausible is behavioral differences between extinct and present-day carnivores-in particular, more contact between the teeth of predators and the bones of prey due to more thorough consumption of carcasses by the extinct species. Such thorough carcass consumption implies to the researchers either that prey availability was low, at least seasonally, or that there was intense competition over kills and a high rate of carcass theft due to relatively high predator densities.
翻譯:
一項(xiàng)最近的研究為更新世晚期的捕食者-獵物動(dòng)力學(xué)提供了線索。研究者對(duì)比了現(xiàn)存肉食動(dòng)物同生活在36,000至10,000年前的肉食動(dòng)物以及保存在洛杉磯Rancho La Brea天然瀝青坑的肉食動(dòng)物的牙齒斷裂的數(shù)量。與現(xiàn)存物種相比,已滅絕物種的破損頻率明顯更高。
在考慮這個(gè)發(fā)現(xiàn)的可能解釋時(shí),研究者對(duì)人口統(tǒng)計(jì)學(xué)錯(cuò)誤不予理會(huì),因?yàn)樵诨瘶颖局,(使用的)更老的個(gè)體(樣本)并未超過適當(dāng)比例。他們不同意保存錯(cuò)誤,因?yàn)閮蓚(gè)完全沒有牙齒破裂的物種證明了斷裂不是由坑內(nèi)磨損引起。他們也排除了地域錯(cuò)誤因?yàn)閺钠渌率赖貐^(qū)采集到的牙齒破損數(shù)據(jù)同La Brea的數(shù)據(jù)類似。研究者認(rèn)為最可能的解釋是已滅絕肉食動(dòng)物和現(xiàn)存肉食動(dòng)物間的行為差異--特別是因?yàn)橐褱缃^物種咀嚼動(dòng)物殘骸更加徹底,那時(shí)的捕食者牙齒與獵物骨骼有更多的接觸。這種對(duì)動(dòng)物殘骸的徹底咀嚼向研究者暗示:或者(當(dāng)時(shí))缺乏獵物,至少是季節(jié)性缺乏,或者因?yàn)椴妒痴呙芏认鄬?duì)較高捕食競(jìng)爭(zhēng)很激烈,而且動(dòng)物殘骸失竊率也很高。
重要閱讀技巧:
要快速把握本文,最關(guān)鍵的一個(gè)技巧是在讀第二段前半段,即關(guān)于三種不靠譜的解釋的時(shí)候,要學(xué)會(huì)略讀和跳讀。第二段開頭幾句話呈現(xiàn)出明顯的排比結(jié)構(gòu),以三組“負(fù)評(píng)價(jià)動(dòng)詞+because”組成:“dismissed…because…; rejected…because…; ruled out…because…”。第一次閱讀文章讀到此處時(shí),應(yīng)選擇跳讀,只看科學(xué)家們排除什么解釋(即三個(gè)bias),而不細(xì)看because后面的內(nèi)容。迅速找到接下來說的most plausible的解釋,再詳讀。當(dāng)題目考到三種不靠譜解釋內(nèi)部的邏輯關(guān)系時(shí),才回頭細(xì)看because分句解題。此技巧歸結(jié)為一句話,即:連續(xù)出現(xiàn)的并列或排比結(jié)的細(xì)節(jié)內(nèi)容可跳讀。
讀完文章后,可做如下筆記,整理各句大意及句間關(guān)系:
Recent study:
Tooth fracture: present < RLB
Explanations:
demog. bias Ө
preserv. bias Ө
local. bias Ө
behavioral diff. ⊕
“ low prey / intense competition
3. 做題: 1. The primary purpose of the passage is to
(A) present several explanations for a well-known fact
(B) suggest alternative methods for resolving a debate
(C) argue in favor of a controversial theory
(D) question the methodology used in a study
(E) discuss the implications of a research finding
評(píng): 1)主旨題:正確答案為(E)。本文屬于解釋型文章,全文態(tài)度應(yīng)為正態(tài)度或無態(tài)度,因此應(yīng)排除負(fù)態(tài)度選項(xiàng)。
2)錯(cuò)項(xiàng)分析:
(A): 無中生有:文中并沒有提到這是個(gè)well-known fact
(C): 無中生有:文中并沒有resolve a debate。
(D): controversial是負(fù)評(píng)價(jià)詞,選項(xiàng)屬于負(fù)評(píng)價(jià)選項(xiàng),應(yīng)排除。
(E):question作動(dòng)詞意為質(zhì)疑,是負(fù)評(píng)價(jià)詞,選項(xiàng)屬于負(fù)評(píng)價(jià)選項(xiàng),應(yīng)排除。
2. According to the passage, compared with Pleistocene carnivores in other areas, Pleistocene carnivores in the La Brea area
(A) included the same species, in approximately the same proportions
(B) had a similar frequency of tooth fractures?
(c) Populated the La Brea area more densely
(D) consumed their prey more thoroughly
(E) found it harder to obtain sufficient prey
評(píng): 1)直接細(xì)節(jié)題:正確答案為(B)。題干中出現(xiàn)compared with…, P carnivores in LB area…,問的是比較關(guān)系,比較主體是P carnivores in LB area,參照對(duì)象是P carnivores in other areas。定位至文中15行說local bias處,找到”similar“,即可選到同義轉(zhuǎn)述的正確答案(B)。
2)錯(cuò)項(xiàng)分析:
(A): 無中生有:文中并沒有提到species 內(nèi)的proportions。
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