求助OG12的阅读第7题

安吉拉丁白痴痴

看来两个帖子。还是没怎么明白~求高手解答啊~~~
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.

7. The researchers’ conclusion concerning the absence of demographic bias would be most seriously 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 did 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 carnivores
不明白A为什么不对？
In considering possible explanations for this finding, the researchers dismissed demographic bias because older individuals were not overrepresented in the fossil samples.意思是不是老人的骨头并没有在那些samples中有特殊的代表作用，所以推出researchers不考虑demographic bias？我能理解OG中的解释说This implies that older carnivores would be expected to have more tooth fractures than younger ones.但这跟做题又有什么关系啊？A选项是说越老的话骨头断裂越多，这不是相当于否定了原文中的“老人的骨头并没有在那些samples中有特殊的代表作用”这句话么？

nidesumiao

你标出来的这句话的意思是说，专家们认为，骨骼破碎程度的差异不是由于人口学上的差异造成的，因为化石中,老年标本的比例没有过高（老年的人和动物骨骼松软,牙齿更容易断裂).
而要削弱这种观点,就要说:这种差异是由于老年标本比例过高造成的,也就是d选项,科学家把老年样本当成青年样本了
overrepresented的意思不是你说的特殊代表作用,而是比例过高的意思,造成统计数据不够科学.
你说的a项,越老牙越松,只是在陈述众所周知,甚至是文章默认的一种事实,对题干没有任何的削弱作用

安吉拉丁白痴痴

你标出来的这句话的意思是说，专家们认为，骨骼破碎程度的差异不是由于人口学上的差异造成的，因为化石中,老年标本的比例没有过高（老年的人和动物骨骼松软,牙齿更容易断裂).
而要削弱这种观点,就要说:这种差异是由于老年标本比例过高造成的,也就是d选项,科学家把老年样本当成青年样本了
overrepresented的意思不是你说的特殊代表作用,而是比例过高的意思,造成统计数据不够科学.
你说的a项,越老牙越松,只是在陈述众所周知,甚至是文章默认的一种事实,对题干没有任何的削弱作用

-- by 会员 nidesumiao (2011/8/9 17:55:37)

你把overrepresent的意思一解释我好像就明白啦~~~太谢谢你啦~~~