问大家LSAT逻辑Set 1-8，我死也想不明白。。。

cecilewang

8. Neuroscientists are making progress in discovering more about the cause of Alzheimer’s disease. Alzheimer’s disease patients suffer from dementia and sever memory loss. Autopsies performed on such patients have revealed the presence of brain lesions caused by abnormal protein deposits. Similar deposits are also found in the brains of elderly patients who do not suffer from Alzheimer’s disease. It follows that everyone who lives long enough will eventually develop Alzheimer’s disease.

Which one of the following statements, if true, most seriously undermines the conclusion that everyone who lives long enough will eventually develop Alzheimer’s disease?

(A) The lesions found in the brains of non-Alzheimer’s disease patients are far less extensive than those found in the brains of Alzheimer’s disease patients.

(B) The developing brain produces a greater number of cells than it will ever use. The extra cells are later destroyed by what biologists call "programmed cell death."

(C) The procedure that allows scientists to discover the presence of protein deposits during an autopsy is not yet refined enough to ensure detection of the lesions in all patients.

(D) Autopsies have shown that some people lack the chemical necessary for protein deposits to cause brain lesions.

(E) Though most Alzheimer’s disease patients develop the disease when they are in their late fifties to early seventies, the frequency of patients who develop the disease in their forties is on the rise.
  

答案是D，为什么不是E呢？BTW，D我也没明白为什么most seriously undermine原文中的结论。。。

非常感谢～

286的幸福观

The stimulus takes for granted that "the presence of brain lesions" causes Alzheimer’s disease and that eldly person would inevitablely have brain lesions,and then suggests eldly person would suffer Alzheimer’s disease.But D says "not everyone have chemical necessary to cause brain lesions-even if someone is old enough,he or she would not necessarily have brain lesions."

D,how do you know which one lives long enough?It is out of scope.

[此贴子已经被作者于2008-12-21 15:36:49编辑过]

crusoecrusoe

本题问的是以下哪一项削弱了结论，即削弱“protein deposits 导致 brain lesions（Alzheimer’s disease）”的逻辑联系。

A间接加强

B无关选项

C无关选项（与解剖技术无关）

D削弱（因为 less protein deposits 也导致 brain lesions，所以削弱了起二者的直接关系）

E无关选项（与年龄无关）

taoransk

(D)Autopsies have shown that some people lack the chemical necessary for protein deposits to cause brain lesions
解剖显示有些人会因缺乏蛋白质沉淀所需的化学成因而导致脑损伤

这个和一般习惯的逻辑不一样.....问的是如何攻击年老的人一定得Alzheimer’s disease
材料里的逻辑是 Alzheimer’s disease 是 记忆损伤等, Alzheimer’s disease因脑损伤引起, 年老的人有脑损伤, 所以年老的人得病

一般来说攻击的都是年老的不一定得病之类, (D) 是在没有否认结论的情况下直接说不一定年老才有脑损伤,即不一定年老才得病....... 很奇怪的弯子, 我也没想通虽然其他的也更不对, 但是这个并没有攻击到实质啊

难道说, 一是most, 其他都不是就只有这个了, 二是weaken question是允许'new' information的所以包含out of scope的信息是可以的........恩我就只能这么解释了

sdcar2010

From the premises:
Alzheimer's patient has BOTH brain lesion and protein deposit.
Non-Alzheimer elderly has protein deposit.
Protein deposit is hypothesized to cause brain lesion.

Conclusion: Everyone who lives long enough will eventually develop Alzheimer’s disease

Answer D: some people lack the chemical necessary for protein deposits to cause brain lesions.  
Translation: protein deposit itself won't cause brain lesions.  You also need the presence of a particular chemical.  Hence, Those elderly who lack the chemical and live long enough will not develop Alzheimer's disease.

fukaimao

(D)Autopsies have shown that some people lack the chemical necessary for protein deposits to cause brain lesions
解剖显示有些人会因缺乏蛋白质沉淀所需的化学成因而导致脑损伤

这句话翻译的不对吧，应该是有些人因为缺乏蛋白质沉淀所需的化学成因因而（无法）导致脑损伤。
简单的说就是这题说科学家寻找疾病的成因，在有些患病的老年人身上发现有缺乏蛋白质沉淀的脑损伤，在另外一些同年龄的人身上发现有蛋白质沉淀但是没有脑损伤，所以得出结论人活到一定岁数（有蛋白质沉淀）终将导致这个疾病。
D选项削弱结论，因为就算有些人缺乏蛋白质沉淀，但因为没有化学成因，所以终将无法导致脑损伤，也就无法得病。直接削弱原文结论。

taoransk

(编辑取消)

sdcar2010

(D)Autopsies have shown that some people lack the chemical necessary for protein deposits to cause brain lesions
解剖显示有些人会因缺乏蛋白质沉淀所需的化学成因而导致脑损伤

这句话翻译的不对吧，应该是有些人因为缺乏蛋白质沉淀所需的化学成因因而（无法）导致脑损伤。
简单的说就是这题说科学家寻找疾病的成因，在有些患病的老年人身上发现有缺乏蛋白质沉淀的脑损伤，在另外一些同年龄的人身上发现有蛋白质沉淀但是没有脑损伤，所以得出结论人活到一定岁数（有蛋白质沉淀）终将导致这个疾病。
D选项削弱结论，因为就算有些人缺乏蛋白质沉淀，但因为没有化学成因，所以终将无法导致脑损伤，也就无法得病。直接削弱原文结论。

-- by 会员 fukaimao (2010/11/5 14:26:59)

(D)Autopsies have shown that some people lack the chemical necessary for protein deposits to cause brain lesions

The correct translation should be:
解剖显示有些人缺乏让蛋白质沉淀导致脑损伤所必需的化学成因

The sequence is 1) protein deposits; 2) a chemical that cause the protein deposits to produce brain lesions; 3) protein lesion.

lovepunch

同意sdcar2010 这个理解！D是削弱，说deposit不一定会导致脑损伤~其它选项无关吧

旺财财

看过谢谢lz~~~~~