【尚友制造】wangyu73cn之阅读加油站

标题：wangyu73cn之阅读加油站（OG37-234）尚友论坛【GMAT专区】【尚友学堂GMAT公开课】【GMAT机经专区】【GMAT资料下载区】【GMAT黄历查询】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.234. The researchers’ conclusion concerning the absence of demographic bias would be mostseriously undermined if it were found that(A) the older as individual carnivore is, the more likely it is to have a large number of tooth fratures (B) the average age at death of a present-day carnivores 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 younger individuals(D) the methods used to determine animals’ ages in fossile 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 carnivores234. This question asks you to identify a statement that would undermine the researchers’ conclusion regarding demographic bias.本题考察逻辑关系、名词定位两个问题 The researchers concluded that demographic bias was not a factor because older individuals were not disproportionately represented among the fossils. 这是原文的改写The implication of this conclusion is that older individuals might be expected to have a higher rate of tooth breakage. 这说明文章中需注意的隐含意思。

The best answer is D. 给出答案。

bestThe researchers’ conclusions with regard to the demographic bias are depended upon reliable information about the age of the individuals in the fossil samples. 说明了逻辑的关键点在于年龄的分布信息。

If there were a demographic bias-in this case, a preponderance of older individuals-in the fossil samples, the misidentification of older individuals as younger ones would have concealed the bias from researchers. 指出D选项中所述的情况，即将老的个体当作新的个体，抓住了年龄分布这一关键点，揭示了确实存在统计分布偏差。

Choice A is not correct. A的错误形式比较特殊，需注意The researchers’ conclusions imply that older individuals might be expected to have a higher rate of tooth breakage. 这再次说明文章中需注意的隐含意思。

Findings th at confirmed this would not undermine the researchers’ conclusions that the samples were representative.文章内容中已包含的隐含意思不可能对论述构成进一步的削弱作用。

即文章内容的确认不能对论述本身发生额外作用。

这实际上是逻辑题目中经常需要注意的问题。

The information in choice B, C and E is irrelevant to the issue of whether older individuals were disproportionately represented among the fossil sample. 与中心问题无关你看，它们几乎每一句都有用，都需要注意。

而且复杂问题就多说几句，简单问题就一笔带过。

唉，不得不佩服ETS啊the demographic bias are depended upon reliable information about the age of the individuals ，年龄判断错了不就正好说明demographic bias存在么？跟“对研究有影响”这个结论不是一样么？ETS说，The researchers’ conclusions with regard to the demographic bias are depended upon reliable information about the age of the individuals in the fossil samples.他是讲The researchers’ conclusions are depende d upon reliable information。

而你对其主语的判断疏忽了。

是吧？：）还有就是这个句子不明白：The researchers concluded that demographic bias was not a factor because older individuals were not disproportionately represented among the fossils我怎么不明白这个句子的关系？？那个老的不能代表跟偏差不是一个因素有什么关系？？？？我们已知，结论是关于the absence of demographic bias的。

下一步需要定位原文the researchers dismissed demographic bias because older individuals were not overrepresented in the fossil samples。