非常绕的难题，留给大神路过看看呗！

faithjtt

OG 2nd Verbal

问题1 （55 P.207）.There is a great deal of geographical variation in the frequency of many surgical procedures-up to tenfold variation per hundred thousand people among different areas in the numbers of hysterectomies, prostatectomies, and tonsillectomies.

To support a conclusion that much of the variation is due to unnecessary surgical procedures, it would be most important to establish which of the following?

(A) A local board of review at each hospital examines the records of every operation to determine whether the surgical procedure was necessary．
(B) The variation is unrelated to factors (other than the surgical procedures themselves)that influence the incidence of diseases for which surgery might be considered．
(C) There are several categories of surgical procedure(other than hysterectomies，prostatectomies，and tonsillectomies)that are often performed unnecessarily．
(D)For certain surgical procedures，it is difficult to determine after the operation whether the procedures were necessary or whether alternative treatment would have succeeded·
(E) With respect to how often they are performed unnecessarily, hysterectomies, prostatectomies，and tonsillectomies are representative of surgical procedures in general．

这道题我网上也搜过解释了，说的是手术数量地域差异大——很多手术是没有必要的
我选了E，认为这几个病是代表，说明的确有一些手术是没必要的。
答案是B.解释说的是排除他因。
这道题我看了解释还是不太理解
1.因为做了PREP08，我都是按照08里面的分类来看，我把这道题看成了统计枚举。。。。。。。。其实应该是果因把。。总觉得这两个非常的类似。。。。求大神解答。。为什么这道题不应该看做是统计枚举，为什么E选项错了。


统计枚举简直太难以辨认了，我把这道题认为是相思因果

Often patients with ankle fractures that are stable, and thus do not require surgery, are given follow-up x-rays because their orthopedists are concerned about possibly having misjudged the stability of the fracture. When a number of follow-up x-rays were reviewed, however, all the fractures that had initially been judged stable were found to have healed correctly. Therefore, it is a waste of money to order follow-up x-rays of ankle fracture initially judged stable.
Which of the following, if true, most strengthens the argume? (C)

A)        Doctors who are general practitioners rather than orthopedists are less likely than orthopedists to judge the stability of an ankle fracture correctly.
B)        Many ankle injuries for which an initial x-ray is ordered are revealed by the x-ray not to involve any fracture of the ankle.
C)        X-rays of patients of many different orthopedists working in several hospitals were reviewed.
D)        The healing of ankle fractures that have been surgically repaired is always checked by means of a follow-up x-ray.
E)        Orthopedists routinely order follow-up x-rays for fractures of bone other than ankle bones

问题2：OG 2nd Verbal
41. Dental researchers recently discovered that tooth-brushes can become contaminated wth bacterial that cause pneumonia and strep throat. They found that contamination usually occurs after toothbrushes have been used for four weeks. For that reason, people should replace their toothbrushes at least once a month.
Which of the following, if true, would most weaken the conclusion above?
(A) The dental researchers could not discover why toothbrush contamination usually occurred only after toothbrushes had been used for four weeks.
(B) The dental researchers failed to investigate contamination of toothbrushes by viruses, yeasts, and other pathogenic microorganisms.
(C) The dental researchers found that among people who used toothbrushes contaminated with bacterial that cause pneumonia and strep throat, the incidence of these diseases was no higher than among people who used uncontaminated toothbrushes.
(D) The dental researchers found that people who rinsed their toothbrushes thoroughly in hot water after each use were as likely to have contaminated toothbrushes as were people who only rinsed their toothbrushes hurriedly in cold water after each use.
(E) The dental researchers found that, after six weeks of use, greater length of use of a toothbrush did not correlate with a higher number of bacterial being present.

这一题是我认为是因果，
在牙刷用了四个礼拜发现了致病的细菌—所以应该每个月换一次牙刷
为了对原因weaken,4个礼拜发现病菌。
所以我就选了E.


感觉思维有漏洞啊。尤其是分类。。求大神解惑和建议。

faithjtt

DDDDDDDDDDDDDDDDDDDDDD要看到啊各位

ybonne

题目的关键不是有没有必要做手术, 而是这三种手术的数量很多. 所以关键是数量的逻辑, 不是需要还是不需要的逻辑. 所以E是错误的.

毕出-Helr

解答1：
这个题目确实是果因推理。整个推理文段其实是给出了一个现象，问题给出了一个解释。这种现象解释型的一般都是果因推理。那么，果因推理和枚举推理的区别是什么呢？确实，它们两个看起来都是一种总结性的说法。实际上，两者具有本质的区别。我举两个例子：
(1)因为小明很胖，所以大家应该都挺胖的。
(2)因为小明很胖，所以他肯定喜欢吃垃圾食品。
(1)是枚举推理；(2)是果因推理。两者最明显的区别在于，枚举推理中，前提说的内容在结论中会重复，这样才能形成枚举，比如(1)中的“胖”。果因推理中，结论是要提出前提的一个内因，两句话的内容不可能相同。
在这道题目中，结论明显是提出了一个内因嘛，所以是果因推理。在已知推理方式的情况下，相信你选出答案应该不是难事了。

相“思”因果。这是你的独门秘籍吧哈哈~  问题1里的这个第二个小题，按照刚才讨论的做法，你看，前提中给出了这么一句话：
When a number of follow-up x-rays were reviewed, however, all the fractures that had initially been judged stable were found to have healed correctly.
结论中的说法非常生活化，说的是：这个follow-up x-rays根本就是浪费钱的。这个结论什么意思呢？什么叫做浪费钱？实际上，所谓浪费钱，就是这个follow-up x-rays做了也没用，也就是说，所有的这些follow-up x-rays所照的踝关节骨折这种病都是没问题的（这才叫做了也没用嘛）。由此可以判断本推理为枚举推理。这个题目算是枚举推理中最难的啦，要理解清楚题意才行。

毕出-Helr

解答2：
这道题目就是相“思”因果了。相关因果推理的定义是：从相关到因果的推理是一个基于两个事件的相关关系，推理出其中一个事件引起另一个事件的推理。
结论中表达两个事件是“导致”关系的，除了最常见的用cause等词汇外，还可以用“目标—计划”的方式来表达，例如：
前提：我发现，在ChaseDream网站上，凡是刷了8次GMAT OG的人最后GMAT都考了740分以上。
结论：为了考740以上，咱们去刷OG吧！

对于这道题目来说，它的前提中给出了“牙刷感染细菌”和“人类感染细菌”之间的时间关系（4周之后），结论用了一个目标计划的形式建立了两者的联系，因此肯定是相关因果推理啊~
C选项是一个典型的CQ1：相关性不存在~

lainemai

解答第一个，因果关系gmat考的无外乎三种如果题干给出A导致B，那么有可能出现：**因果倒置，有可能是B导致A；**排除他因，可能是C导致的A；**可能A和B本身就是两个独立事件，没有因果干系，很显然第一题可能是其他原因，导致variation，所以要排除这个原因......

faithjtt

毕出-Helr 发表于 2015-1-27 16:58
解答1：
这个题目确实是果因推理。整个推理文段其实是给出了一个现象，问题给出了一个解释。这种现象解释型 ...

啊啊啊啊啊啊 好激动 居然遇到大神解惑！！
在做您编辑的08呢！！非常感谢 解答我的问题！08编得棒棒的！！

毕出-Helr

faithjtt 发表于 2015-1-29 14:12
啊啊啊啊啊啊 好激动 居然遇到大神解惑！！
在做您编辑的08呢！！非常感谢 解答我的问题！08 ...

加油！

万事屋小白

卤煮！我还是没懂...
第一题， 是因为选项B中说导致variation的其他原因都排除了，所以就是支持了很多手术是不必要的结论吗？

2643301345

lainemai 发表于 2015-1-29 09:35
解答第一个，因果关系gmat考的无外乎三种如果题干给出A导致B，那么有可能出现：**因果倒置，有可能是B导致A ...

同意！