【求助】GWD的一道CR题，关于取非削弱

ileroyoverstep · 发表于 2015-8-21 09:53:13

下面这道题我很疑惑D答案，D答案的元素“土壤中有没有有利于花长高的物质”应该是个关键点吧，这个选项错误是否是因为问法不对？是否换个问法就能当作一个比较合理的答案？这个着实不太懂，求NN赐教，下面是自己的逻辑链：

Two centuries ago, Tufe Peninsula became separated form the mainland, isolating on the newly formed Tufe Island a population of Turfil sunflowers. This population's descendants grow to be, on average, 40 centimeters shorter than Turfil sunflowers found on the mainland. Tufe Island is significantly drier than Tufe Peninsula was. So the current average height of Tufe's Turfil sunflowers is undoubtedly at least partially attributable to changes in Tufe's environmental conditions.
Which of the following is an assumption on which the argument depends?

A There are no types of vegetation on Tufe Island that are known to benefit from dry conditions.
B There were about as many Turfil sunflowers on Tufe Peninsula two centuries ago as there are on Tufe Island today.
C The mainland's environment has not changed in ways that have resulted in Turfil sunflowers on the mainland growing to be 40 centimeters taller than they did two centuries ago.
D The soil on Tufe Island, unlike that on the mainland, lacks important nutrients that help Turfil sunflowers survive and grow tall in a dry environment.
E The 40-centimeter height difference between the Turfil sunflowers on Tufe Island and those on the mainland is the only difference between the two populations.
这道题的我逻辑链大概是这样子的：
background：两个世纪前，tufe半岛和是和大陆分离的
               tufe半岛的花trufil比大陆的turfil花矮40cm
               tufe半岛比大陆干很多

               环境因素影响---->tufe的花矮

所以最后用reebe的方法分析下来是：
推理-->事实：
【取非选择最削弱】
这里首先可以通过无关排除ABE，然后剩下CD，分别取非削弱的话，可以知道C“有其他因素导致大陆的花变高”其实更加削弱（它因影响），而D选项取非则是“土壤中没有缺少让花存活、长高的元素”

ileroyoverstep · 发表于 2015-8-21 09:55:10

自己顶一个！DDDDDDDDDDDDDDDDDDDDDDDDDDDDD

ileroyoverstep · 发表于 2015-8-21 10:40:53

这里再弱弱问一下，假如取非的话是取非“主谓宾”的哪一环啊？

alzn2765 · 发表于 2015-8-21 13:01:38

这题就是GMAT CR最喜欢考的“相对与绝对”：

如果你仔细读题，你会发现作者在比较的时候做了一个假设：作为被比较对象的Tufe on Mainland，假设其在过去Two centuries是没有变化的。否则其结论不能有效成立：Tufe on island比Tufe on Mainland矮---->island 干旱。如果是Tufe on island在过去Two centuries是没有变化，而Tufe on Mainland长高了呢？果因推理显然就无法成立了。C正是排除了这样一个可能使得结论无法成立的可能性。

虽然CD经过Negation Test看起来似乎都可以削弱结论，但是Assumption是结论成立的一个必要条件（有之未必然，无之必不然），而他因可能是既不充分也不必要条件。

C取否--->结论无法成立。
D取否--->结论不一定无法成立。D可能是他因之一，也许并不是因为D这个他因，而是因为其他的他因。

这题是前提结论搭桥题，没有这个“桥”，结论无法成立。

ileroyoverstep · 发表于 2015-8-22 15:31:13

alzn2765 发表于 2015-8-21 13:01
这题就是GMAT CR最喜欢考的“相对与绝对”：

如果你仔细读题，你会发现作者在比较的时候做了一个假设：作 ...

嗯，谢谢大侠，这道题我大概懂这个充分必要的问题了，做的时候让我想起了一道GWD争议题里面的A选项，虽然正确答案C选项和这里的C选项相当相似（题目在下方），都是说”对比的时候变量唯一，没有它因干扰“，但是迷惑选项A的话就比这道题的D选项tricky很多，取非谓语后是是“不上课可能阻止任何人犯罪”，虽然很绝对，但是感觉是说明了这个政策“一定有用or一定没用”

Newspaper editorial:In an attempt to reduce the crime rate, the governor is getting tough on criminals and making prison conditions harsher. Part of this effort has been to deny inmates the access they formerly had to college-level courses. However, this action is clearly counter to the governor's ultimate goal, since after being released form prison, inmates who had taken such courses committed far fewer crimes overall than other inmates.

Which of the following is an assumption on which the argument depends?

A Not being able to take college-level courses while in prison is unlikely to deter anyone from a crime that he or she might otherwise have committed.
B Former inmates are no more likely to commit crimes than are members of the general population.
C The group of inmates who chose to take college-level courses were not already less likely than other inmates to commit crimes after being released.
D Taking high school level courses in prison has less effect on an inmate's subsequent behavior than taking college-level courses does.
E The governor's ultimate goal actually is to gain popularity by convincing people that something effective is being done about crime.

alzn2765 · 发表于 2015-8-23 10:34:03

ileroyoverstep 发表于 2015-8-22 15:31
嗯，谢谢大侠，这道题我大概懂这个充分必要的问题了，做的时候让我想起了一道GWD争议题里面的A选项，虽然 ...

C是结论成立的必要条件，C取否则结论一定不成立。

C的意思是“样本没有“特殊性”：那些读了课程的罪犯不是本来就不会再犯的那些人

A牟定了一个“他因”是导致这个结果的唯一必要条件，可事实并非如此：也许是因为监狱里没有PS4人们才害怕进监狱呢？

ileroyoverstep · 发表于 2015-8-23 17:24:42

alzn2765 发表于 2015-8-23 10:34
C是结论成立的必要条件，C取否则结论一定不成立。

C的意思是“样本没有“特殊性”：那些读了课程的罪犯 ...

嗯嗯，忽然有点感悟了。对于唯一性的问题的话，那我试着按照正的思路走的话，就是“不上课不可能阻止任何人犯罪”，这原文事实相悖，因为原文只是reduce crime rate，并非绝对词，所以之前肯定有着一定数目的“被阻止犯罪的人”。结合这点的话，这个有着only+any的选项一定是错误的！请问按照NN 的思路走这样是否是对的？

AnnAys · 发表于 2016-7-7 04:45:08

alzn2765 发表于 2015-8-21 13:01
这题就是GMAT CR最喜欢考的“相对与绝对”：

如果你仔细读题，你会发现作者在比较的时候做了一个假设：作 ...

此贴已收录至《Alzn大神CD答疑集合》。

AnnAys · 发表于 2016-7-7 04:45:51

alzn2765 发表于 2015-8-23 10:34
C是结论成立的必要条件，C取否则结论一定不成立。

C的意思是“样本没有“特殊性”：那些读了课程的罪犯 ...

此贴已收录至《Alzn大神CD答疑集合》。

【求助】GWD的一道CR题，关于取非削弱

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