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lawyer老师既然做了版主, 我这个平常受益多多的学生得贡献一把
如果你是一个和我一样入门级的菜鸟, 那么下面我平时收集的一些lawyer的逻辑题分析一定会对你有或多或少的帮助.大家可以结合lawyer的"考试时如何做逻辑"一起看. lawyer的文章可以给大家理论上的帮助, 那么再看这里的具体分析, 体会做逻辑题的思路.一定会快速进步)希望如此啦)(我以后在学习的过程中还会往里面再添加, 让我们一起提高)
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To be horrific, a monster must be threatening. Whether or not it presents psychological, moral, or social dangers, or triggers enduring infantile fears, if a monster is physically dangerous then it is threatening. In fact, even a physically benign monster is horrific if it inspires revulsion.
Which one of the following logically follows from the statements above?
(A) Any horror-story monster that is threatening is also horrific.
(B) A monster that is psychologically dangerous, but that does not inspire revulsion, is not horrific.
(C) If a monster triggers infantile fears but is not physically dangerous, then it is not horrific.
(D) If a monster is both horrific and psychologically threatening, then it does not inspire revulsion.（E）
(E) All monsters that are not physically dangerous, but that are psychologically dangerous and inspire revulsion, are threatening
1。 列出原文逻辑关系：horrific--->threatening, physically dangerous---->horrific, inspire revulsion--->horrific
2。将选项和原文逻辑关系对：否命题和逆命题都错。只有逆否命题和原命题对。同时排除不参与逻辑关系的选项
3。A：threatening ---> horrific 逆命题。错
B：psychologically dangerous不参与逻辑关系，不管。does not inspire revulsion--->not horrific否命题。错
C：triggers infantile fears 不参与逻辑关系。不管。not physically dangerous----> not horrific.否命题。错
D：原文没此逻辑关系。
E：psychologically dangerous and inspire revulsion是inspire revulsion的子概念。原文的inspire revulsion--->horrific--->threatening.则E也对。
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. No mathematical proposition can be proven true by observation. It follows that it is impossible to know any mathematical proposition to be true.
The conclusion follows logically if which one of the following is assumed?
(A) Only propositions that can be proven true can be known to be true
(B) Observation alone cannot be used to prove the truth of any proposition
(C) If a proposition can be proven true by observation then it can be known to be true.
(D) Knowing a proposition to be true is impossible only if it cannot be proved true by observation
(E) Knowing a proposition to be true requires proving it true by observation
我给这道题的目的有两个：1是说明充分型假设（假设选项，原文结论能合理推出）的TEST（答案检验法）。2是这种题易混的答案。
1。充分型假设的TEST：将选项加入到原文推理中，看看能否推出原文结论。即：正确答案+原文前提=原文结论。
2。这种题最易混的答案为：相反的推理。即变为从结论往前提推。而正确答案常是以逆否命题的面目出现。所以增加了难度。
3。做法：一是找出原文的推理。特别注意从那里推向那里。二是找出推理中的GAP。排除没有这个GAP的概念的选项，剩下常只有两个。看着两个那个是推理相反的选项，排除掉它。剩下的就是正确的。或者用TEST去对，看那个符合TEST。
该题：推理：因为 mathematical proposition NO PROVE BY OBSERVATION， 所以mathematical proposition IMPOSSIBLE KNOW TO BE TRUE(概念跳跃为PROVE By observation，KNOW)。推理方向从NO PROVE BY OBSERVATION到 IMPOSSIBLE KNOW。（注意：这里没有充分必要关系，即不能将原文写成NO PROVE BY OBSERVQATION---〉IMPOSSIBLE KNOW。）
A：意思为proposition KNOWN TO BE TRUE---> ROPOSITION CAN BE PROVE。该选项很容易混。因为推理方向对：逆否命题从NO PROVE 到IMPOSSIBLE KNOW。且概念也很象，包含和被包含的概念（proposition包含mathematical proposition），概念比原文大在这类题中是允许的。但它错在没有说明PROVE的方式，原文有说明PROVE的方式为BY OBSERVATION。这也是和E选项的唯一区别。所以A选项加BY OBSERVATION便为答案。
B：没有KNOW的概念。错
C：CAN BE PROVE BY OBSERVATION---〉 KNOWN TO BE TRUE。逆否命题为IMPOSSIBLE KNOWN TO BE TRUE--->CANNOT BE PROVE BY OBSERVATION。和原文推理相反。错
D：IMPOSSIBLE KNOWN TO BE TRUE--->CANNOT BE PROVE BY OBSERVATION.和原文推理相反。错。
E：KNOWN TO BE TRUE--->CAN BE PROVE BY OBSERVATION（注意REQUIRE带必要条件）。逆否命题为：CANNOT BE PROVE BY OBSERVATION---〉IMPOSSIBLE KNOWN TO BE TRUE。和原文推理方向一致。正确答案。
注明：该题较特殊。除了两个推理相反的选项。还有一个概念相似的混淆项。
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One year ago a local government initiated an antismoking advertising campaign in local newspapers which it financed by imposing a tax on cigarettes of 20 cents per pack。 One year later the number of people in the locality who smoke cigarettes had declined by 3 percent。 Clearly what was said in the advertisements had an effect， although a small one on the number of people in the locality who smoke cigarettes.
Which one of the following, if true, most helps to strengthen argument?
(A) Residents of the locality have not increased their use of other tobacco products such as snuff and chewing tobacco since the campaign went into effect
(B) A substantial number of cigarette smokers in the locality who did not quit smoking during the campaign now smoke less than they did before it began
(C) Admissions to the local hospital for chronic respiratory ailments were down by 15 percent one year after the campaign began
(D) Merchants in the locality responded to the local tax by reducing the price at which they sold cigarettes by 20 cents per pack
(E) Smokers in the locality had incomes that on average were 25 percent lower than those of nonsmokers
1。对于SUPPORT，ASSUMPTION和WEAKEN题，要特别重视结论的具体性和特殊性（我在“考试时如何做逻辑题”说过）。这就是这几类题排除有关无关的依据，有时单凭这点就排除无关项后只剩答案。结论的具体性和特殊性就是要精确理解结论，理解每部分在原文中的的精确的具体的含义（结合证据），是这意思，不是那意思，是指这个，不是指那个。它是讲个方面的问题，讲的是什麽，具体情况如何。这点无论如何强调都不过分。
2。具体到本题，结论是：广告所说的内容有效果。这是在讨论政府的禁烟广告是否有作用，在讲广告对禁烟的作用，它的效果在原文体现在一年后本地人吸烟人数减少3%（证据）。这个效果是指抽烟人数减少，不是指别的效果。这就是结论的特殊性和具体性。
A。好像是排除他因。但它讲的效果是用别的烟产品的效果，不是抽烟的效果，它讲的是用的频率没有增加的效果，不是吸烟人数减少的效果。故无关
B。它讲的是用的量的效果，是程度的效果，不是人数多少的效果。故错
C。易排除
D。对广告对抽烟人数减少的效果，排除一种可能。即抽烟人数减少有可能是烟太贵了（加税），D排除这种可能，故加强结论。
E。没钱，那就别抽烟，没钱又不是发生在广告后。无关。
3。其实大家有没有看出结论是因果型结论，结论可说成是：本地政府的广告导致抽烟人数减少3%。因果型结论的支持方式之一是排除其他原因。
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Shipping Clerk: The five specially ordered shipments sent out last week were sent out on Thursday. Last week, all of the shipments that were sent out on Friday consisted entirely of building supplies, and the shipping department then closed for the weekend. Four shipments were sent to Truax Construction last week, only three of which consisted of building supplies.
If the shipping clerk’s statements are true, which of the following must also be true?
At least one of the shipments sent to Truax Construction last week was specially ordered. At least one of last week’s specially ordered shipments did not consist of building supplies. At least one of the shipments sent to Truax Construction was not sent out on Thursday of last week. At least one of the shipments that were sent out on Friday of last week was sent to Truax Construction. At least one of the shipments sent to Truax Construction last week was sent out before Friday. A。错。原文看不出Four shipments to Truax Construction last week 和第一句的 five specially ordered shipments 有何关系。错
B。错。因为不知道上周四的SHIPMENT中是否包括SUPPLIES，只知道周五的都有。故不知T周四送出的 five specially ordered shipments 是否有SUPPLIES。
C。错。周四送多少去Truax Construction ，或有没有送，原文不知道。
D。错。原文只知道去Truax Construction 有四个，至于何时送，不知道。尽管原文说这四个中，有三个有SUPPLIES，而周五送的都有SUPPLIES，但不知其他时间送的是否也有SUPPLIES，所以不知这三个是否都是周五送。
E。对。周五的都有SUPPLIES，以后就关门了，所以没有SUPPLIES的肯定是周五前送的。即去Truax Construction 中肯定有一个是周五前送的。又因为可能周五前的其他时间送的也包括SUPPLIES，即另外的三个也可能是周五前送的，所以E用“AT LEAST ONE” ---------------------------------------------------------------------------------------------------
Studies in restaurants show that the tips left by customers who pay their bill in cash tend to be larger when the bill is presented on a tray that bears a credit-card logo. Consumer psychologists hypothesize that simply seeing a credit-card logo makes many credit-card holders willing to spend more because it reminds them that their spending power exceeds the cash they have immediately available.
Which of the following, if true, most strongly supports the psychologists’ interpretation of the studies?
The effect noted in the studies is not limited to patrons who have credit cards.
Patrons who are under financial pressure from their credit-card obligations tend to tip less when presented with a restaurant bill on a tray with credit-card logo than when the tray has no logo.
In virtually all of the cases in the studies, the patrons who paid bills in cash did not possess credit cards.
In general, restaurant patrons who pay their bills in cash leave larger tips than do those who pay by credit card.
The percentage of restaurant bills paid with given brand of credit card increases when that credit card’s logo is displayed on the tray with which the bill is prepared 假设和支持的区别。假设是原文结论的必要条件。它错，原文结论必错，所以可以用去非法验证。支持是使结论的说服力更强，它或者直接支持结论，或者是原文证据对结论证明力加强。假设是支持的子集。它可以是结论的必要条件（假设型），也可以不使结论的必要条件。验证的方法是问自己，该答案是否在某方面帮助了作者，使结论的说服力加强。
B是通过加强原文证据对结论的证明力来加强结论。即B说明看到LOGO会让人想到信用卡的状况，从而影响付TIPS行为。如果信用卡的状况是不好，则付TIPS少（B所说），如果信用卡的状况好，则付TIPS多（原文证据），是一个规律的两个方面。所以加强了结论。
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Over the past five years, the price gap between name-brand cereals and less expensive store-brand cereals has become so wide that consumers have been switching increasingly to store brands despite the name brands’ reputation for better quality. To attract these consumers back, several manufacturers of name-brand cereals plan to narrow the price gap between their cereals and store brands to less than what it was five years ago.
Which of the following, if true, most seriously calls into question the likelihood that the manufacturers’ plan will succeed in attracting back a large percentage of consumers who have switched to store brands?
There is no significant difference among manufacturers of name-brand cereals in the prices they charge for their products.
Consumers who have switched to store-brand cereals have generally been satisfied with the quality of those cereals.
Many consumers would never think of switching to store-brand cereals because they believe the name brand cereals to be of better quality.
Because of lower advertising costs, stores are able to offer their own brands of cereals at significantly lower prices than those charged for name-brand cereals.
Total annual sales of cereals—including both name-brand and store-brand cereals—have not increased significantly over the past five years.
原文的推理是：name-brand cereals 生产商计划用将差价缩小的方法将丢失的顾客吸引回来（价格仍然比STORE高，说明主要仍要靠质量吸引顾客，降价只是消除STORE的优势，消除顾客买STORE谷物的原因----理解这点很重要）（方法目的型）
D。STORE有能力提供低价对name-brand cereals 要缩小差价的方法起不了什麽作用，因为STORE价格本来就低，你说STORE有能力提供低价不等于白说吗。
B。name-brand cereals 生产商想要象原来一样靠质量吸引他们，现在这个因素不存在了（顾客现在对STORE的质量满意，不考虑NAME优势）。吸引他们的因素没了。顾客有何理由回去。价格吗?(质量已经不重要)，name-brand cereals 生产商价格降价后还是比STORE高。
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In a recent poll of chief executive officers(CEOs) of 125 large corporations, the overwhelming majority claimed that employee training and welfare is of the same high priority as customer satisfication. So the popular belief that the top management of large corporations behaves indifferently to the needs and aspirations of employees is unfounded.
The argument is most vulnerable to criticism on the grounds that it
A) fails to define adequately the term "top management"
B) presumes, without giving justification, that one is not indifferent to something that one considers a top priority
C) presumes, without giving justification, that the CEOs' priorities tend to be misplaced
D) presumes, without giving justification, that the CEOs' claims are reflected in actual practice
E) makes a generalization based on an unrepresentative sample 1。答案为D，其实该题不难，做错的原因很多出于心理定势。LSAT不少题考这种心理定势：我们习惯了“搭桥（GAP）”，“他因”。所以碰到有选项有这种特点，不少人就选了，即使在其它选项把握不准的情况下。就像本题D选项，它的GAP在原文是有一定程度给人怪怪的感觉，所以很容易漏掉。不幸的是，在我做题的过程中，感觉不少正确答案都有点拐弯抹角，不是很直接，所以建议在时间允许情况下，对怪怪的选项还是要注意一下。
2。E选项的错误MINDFREE已说得很精彩。该题B，D较容易混。
3。原文其实有三个GAP。一个是CEO的CLAIM和BEHAVE（结论中）。另一个是high priority 和not indifferently 。还有一个是employee training and welfare 和the needs and aspirations of employees
4。对于第二个high priority 和not indifferently 的GAP，indifferent本身的意义是not interested in, not caring about or noticing。所以一个人认为一件事high priority ，则不能对那件事 indifferently 。即high priority 和not indifferently 意义一致，THIS SIMPLY FOLLOW FROM THE MEANING OF THE TWO TERMS，不能算GAP，即这点不是原文推理的缺陷，不是推理中易被criticism的地方。所以B错
5。对于第三个，两者在原文的CONTEXT中，意义不同，所以是GAP，是答案，但选项中没有。
6。对于第一个CLAIM和BEHAVE，说和做是无法等同起来的，说一套做一套的人很多，台上说不能贪污，台下自己大贪，所以是GAP，是 vulnerable to criticism 的地方，所以是答案。
补充一下
1。A错误的原因：原文以公司的CEO作为TOP MANAGEMENT的代表是合适的，况且，即使定义了TOP MANAGEMENT，原文的推理也没有更STRONG。所以不是答案。
2。CLAIM来源于原文“the overwhelming majority claimed that 。。。”，正是从这些CEO的CLAIM推出原文的结论：top management 对员工的福利是不会做到indifferently（behaves indifferently to the needs and aspirations of employees is unfounded）。很明显原文的证据是一个CLAIM，结论是不会那末做。
从这道题我们可以得出如何才算GAP（精确讲应该叫逻辑上的跳跃），以便用于假设题中。补充到“逻辑体的大体思路”中。
GAP（逻辑上的跳跃）指原文的推理过程中有概念的跳跃，这个跳跃可以存在证据中，也可以存在证据和结论中（该题存在证据和结论中），这两个概念不仅仅内容不同，关键是逻辑上有跳跃，即逻辑上不能从一个推出另一个（在原文的CONTEXT下），如该题的B选项，就是因为能从PRIORIYT 推出NOT INDIFFERNTLY，所以不存在逻辑上的跳跃。
The importance of the ozone layer to terrestrial animals is that it entirely filters out some wavelengths of light but lets others through. Holes in the ozone layer and the dangers associated with these holes are well documented. However, one danger that has not been given sufficient attention is that these holes could lead to severe eye damage for animals of many species.
Which one of the following is most strongly supported by the statements above, if they are true.
A). All wavelengths of sunlight that can cause eye damage are filtered out by the ozone layer where it is intact.错的原因：All wavelengths 太strong。原文只知完好的臭氧层滤掉一部分光，让一部分通过，并说通过的那部分对很多动物有害。从这点很容易误认有害的都给滤掉了。其实原文没说是否那通过的一部分是否含有有害波长。所以错。
B). Few species of animals live on a part of the earth's surface that is not threatened by holes in the ozone layer错的原因：原文只说有HOLE可能会使很多动物受伤害，从这点也许可以推出有动物生活在受HOLE威胁的地方，但原文没说有没有动物生活在不受HOLE威胁的地方，故错。
C). Some species of animals have eyes that will not suffer any damage when exposed to unfiltered sunlight错的原因：有些人容易选这个，因为原文最后一句话说HOLE会伤害很多动物的眼睛，就是说很多动物的眼睛会受伤害，既然有很多的眼睛受伤害，就有不受伤害的。错。关键是理解原文最后一句话的many。其实相当于some ，表达的是有的概念，就是可以是1-100。相对或取非的概念为NONE。就是说它们可以包括全部100。所以有可能全部动物眼睛都会受HOLE伤害。即C可能对，也可能不对，不是MUST BE TRUE。故错。
D). A single wavelength of sunlight can cause severe damage to the eyes of most species of animals错的原因：也是容易选错，因为原文的最后一句话加上中文对MANY和 MOST（都是很多）的理解。其实MOST（多数）是指51-100。MANY指1-100。所以不能从MANY推出MOST，从MOST倒可以推出MANY。即原文用MOST，D选项用MANY，则为答案。
E). Some wavelengths of sunlight that cause eye damage are more likely to reach the earth's surface where there are holes in the ozone layer than where there are not, 从原文最后两句话可知完好的臭氧层滤掉了部分有害的光线，则说明有洞时，有害的光线更易到达地球。故对。
最后强调一点该问题虽然是MOST STRONGLY SUPPORTED，但不会出现两个能从原文MUST BE得出的答案，因为该题归为MUST BE TRUE题型，当然不存在支持的程度问题。
常见范围词的差别： all(100) most(51 to 100) some are not(0 to 99)(also “Not All”) most are not(0 to 49) some or many(1 to 100) none(0)
[此贴子已经被作者于2004-11-30 1:45:13编辑过] | 
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发表于 2004-11-25 03:16:00
