help~！！！prep 37 逻辑 key is D，我能选出来，但咋想不明白捏~！！！！

bob9603

37.(32356-!-item-!-188;#058&006101)

Capuchin monkeys in Venezuela often rub a certain type of millipede into their fur.Secretions of these millipedes have been shown to contain two chemicals that are potent mosquito repellents, and mosquitoes carry parasites that debilitate the capuchins.The rubbing behavior is rare except during the rainy season, when mosquito populations are at their peak.Therefore, the monkeys probably rub the millipedes into their fur because doing so helps protect them against mosquitoes.

Which of the following would it be most useful to determine in order to evaluate the argument?

(A) Whether the two chemicals provide any protection for the millipedes against their own predators

(B) Whether the type of millipede used by the capuchin monkeys in Venezuela is found in other parts of the world

(C) Whether animals other than capuchins rub insects of any kind into their fur

(D) Whether the only time the millipedes are readily available to the capuchins is during the rainy season

(E) Whether secretions of any other insects accessible to the capuchins contain chemicals that repel mosquitoes

盖里橙

ainiAnnie 发表于 2012-3-4 00:00
我们先来分析题目，Capuchin monkeys in Venezuela often rub a certain type of millipede into their fur ...

同意！               

努力加油

别处看来的，这个答案很清晰了
http://blog.sina.com.cn/s/blog_a6c8856c01018as3.html

要得到这个结论：the monkeys probably rub the millipedes into their fur because doing so helps protect them against mosquitoes. 就是要确定猴子用虫子摩擦皮肤的真正用意是用来驱除蚊子，而不是其他用途。
结论的来源的证据是：
1.     虫子本身具有驱除蚊子的化学物质
2.     猴子摩擦虫子最多的季节是雨季，恰巧雨季也是蚊子最多的季节。

看上去这个证据到这个结论很合理。
但是如果说：这种虫子唯一可获得的季节就是雨季的话，那就很难说猴子摩擦虫子是为了驱蚊。在非雨季的其他季节（蚊子少），猴子没有用虫子摩擦身体并不是因为蚊子少，而是因为猴子根本找不到虫子。言下之意在于，猴子摩擦虫子的季节变化其实与蚊子的数量没什么关系，而是因为虫子只在某个季节出现。那就削弱结论了。

vickizhq

determine跟问削弱加强都一样，重点是影响逻辑链而不是能推出是否。
逻辑链：M能防蚊，猴子就在下雨天经常擦M，下雨天又是蚊子最多的时候，所以推出猴子擦M是为了防蚊；
如果M只在下雨天才有，削弱了逻辑链，因为猴子在下雨天擦M是有条件限制的。
如果M什么时候都有，加强了逻辑链，猴子擦M是没有限制的

bella.uic

ainiAnnie 发表于 2012-3-4 00:00
我们先来分析题目，Capuchin monkeys in Venezuela often rub a certain type of millipede into their fur ...

茅塞顿开~ 谢谢解答

bob9603

Elimination is better for this question.

D is not a good evaluation for this argument because no mater D is established or not we can not make sure that the conclusion in this argument is right or wrong. D just provided a guidance to let us find the assumption between the rubbing and the protection. On the other hand, no other options is useful. So D is the answer.

Elimination can help us to start from the end of the precess above saving our times.

-- by 会员 子弹青春 (2012/3/4 22:04:02)

thank you very much ~!! i get it ~

子弹青春

Elimination is better for this question.

D is not a good evaluation for this argument because no mater D is established or not we can not make sure that the conclusion in this argument is right or wrong. D just provided a guidance to let us find the assumption between the rubbing and the protection. On the other hand, no other options is useful. So D is the answer.

Elimination can help us to start from the end of the precess above saving our times.

ainiAnnie

这道题不是要分析有没有蚊子啊。。。。你思路想歪了。。。。

bob9603

我们先来分析题目，
Capuchin monkeys in Venezuela often rub a certain type of millipede into their fur.Secretions of these millipedes have been shown to contain two chemicals that are potent mosquito repellents, and mosquitoes carry parasites that debilitate the capuchins.
在V地区的monkeys经常rub一种特定的昆虫M使其进入他们的fur，M分泌的物质包含了两种化学成分，是强有效的防蚊剂，and 蚊子是V地区monkeys 的天敌。（简化就是蚊子是Monkeys的天敌，Ms经常使用rub昆虫M，强烈暗示 Ms rub M的原因就是为了防蚊。此时更需警惕！！说不定你已经掉到它的逻辑陷阱了！！）
The rubbing behavior is rare except during the rainy season, when mosquito populations are at their peak.
此处的 rare非常重要，是逻辑漏洞。
这句话说 平时 Ms这种行为很少，然而在下雨天的时候比较频繁，此时刚好蚊子也在高峰期。
Therefore, the monkeys probably rub the millipedes into their fur because doing so helps protect them against mosquitoes.
从而顺利得出结论：Ms rub M 就是问了防蚊。
这里出现了一个逻辑错误：它加强论证的条件认为 同时发生的事情之间必然存在 因果关系。其实不是这样的。答案D提供了另外一种可能，Ms 在雨季 rub 频繁的原因是 只有在雨季才有昆虫M，从而不能顺利推出结论。也是我们评价这个结论最有用的信息。

-- by 会员 ainiAnnie (2012/3/4 0:00:50)

我总感觉是否是only time并不能说明猴子rub是为了对抗蚊子~
我觉得应该是m的有无，才能说明是不是对抗蚊子。有m，则rub m，对抗蚊子；没m，则没有rub这个行为，则对抗不了蚊子~

保险起见，我还是沾过来比较好~

ainiAnnie

我们先来分析题目，
Capuchin monkeys in Venezuela often rub a certain type of millipede into their fur.Secretions of these millipedes have been shown to contain two chemicals that are potent mosquito repellents, and mosquitoes carry parasites that debilitate the capuchins.
在V地区的monkeys经常rub一种特定的昆虫M使其进入他们的fur，M分泌的物质包含了两种化学成分，是强有效的防蚊剂，and 蚊子是V地区monkeys 的天敌。（简化就是蚊子是Monkeys的天敌，Ms经常使用rub昆虫M，强烈暗示 Ms rub M的原因就是为了防蚊。此时更需警惕！！说不定你已经掉到它的逻辑陷阱了！！）
The rubbing behavior is rare except during the rainy season, when mosquito populations are at their peak.
此处的 rare非常重要，是逻辑漏洞。
这句话说 平时 Ms这种行为很少，然而在下雨天的时候比较频繁，此时刚好蚊子也在高峰期。
Therefore, the monkeys probably rub the millipedes into their fur because doing so helps protect them against mosquitoes.
从而顺利得出结论：Ms rub M 就是问了防蚊。
这里出现了一个逻辑错误：它加强论证的条件认为 同时发生的事情之间必然存在 因果关系。其实不是这样的。答案D提供了另外一种可能，Ms 在雨季 rub 频繁的原因是 只有在雨季才有昆虫M，从而不能顺利推出结论。也是我们评价这个结论最有用的信息。