自从23年9月23日GRE改革之后，逻辑单词从之前的每个section1个题目，变成每次考试1个逻辑题，虽然数量变少，但是对于追求高分的同学，仍然不能放弃这个题目，接下来我们介绍一下逻辑单题的常见做题方法。
一般来讲我们看到一篇逻辑题，我们需要对于文章进行分析，一般情况下文章分为两种类型，一种是前提结论，一种是现象解释，并且有的时候会伴随着background，但是背景是不参与我们的论证的，出现可以忽略掉。
🔴举个例子
小明是个学生。 小明偷了同学的东西。 所以，小明今天会被警察抓走。 ⬆️在这个逻辑论证中，我们需要注意 Background：小明是个学生。 Premise：小明偷了同学的东西。 Conclusion：所以，小明今天会被警察抓走。 ⬆️前提和我们的论证没有关系，可以直接省略
今天我们先介绍一下第一种题目论证思路，正在备考的同学赶紧收藏起来吧～
前提结论型文章
理论上讲，我们可以从前提，结论和附加前提三个方面着手。但是单独从前提和结论出发，力度会比较小。接下来我们拿一个中文例子来说明：
🔴中文例题
背景：小明来北京找同学小鹏 前提：小鹏被偷，身上只剩下100块钱来招待到小明 结论：小鹏觉得小明抠门 首先背景和逻辑论证没关系，可以忽略掉
🔻从前提和结论单独论证
前提：假如我们从反驳逻辑论证，说小鹏不是用100块钱来招待小明，是1000块，这种很明显是胡搅蛮缠 结论：假如我们从反驳结论论证，说小明不抠门，就是不叩门，这是很明显直接反对，有点无理取闹； 所以我们要从前提和结论之间的gap着手论证，找additional premise出发论证。
🔻Additional premise
建立一个桥梁：100块钱=抠门 如果花100块钱招待朋友就是抠门，那说明原文逻辑论证是对的 如果花100块钱不一定是抠门，那说明原文的逻辑论证是错的
🔴中文例子
Background：小明是个学生。 Premise：小明很帅。 Conclusion：所以，他的很多同学都很喜欢小明。 对于这个逻辑论证来说，很帅和喜欢中间就有有个gap，有没有可能喜欢一个人的衡量标准不是他的长相呢，有可能智商，情商，财富呢？ 所以要想证明前提能支持结论，我们要加一个additional premise：小明的同学会因为一个人长得帅而喜欢他。
🔻具体题目
When limitations were in effect on nuclear-arms testing, people tended to save more of their money, but when nuclear-arms testing increased, people tended to spend more of their money. The perceived threat of nuclear catastrophe, therefore, decreases the willingness of people to postpone consumption for the sake of saving money.
⛳️The argument above assumes that
A the perceived threat of nuclear catastrophe has increased over the years. B most people supported the development of nuclear arms C people's perception of the threat of nuclear catastrophe depends on the amount of nuclear-arms testing being done D the people who saved the most money when nuclear-arms testing was limited were the ones who supported such limitations E there are more consumer goods available when nuclear-arms testing increases
原文逻辑论证思路
Premise：核武器测试的次数 ⬇️➡️存钱 ⬆️ Conclusion：核灾难的威胁 ⬆️➡️ 存钱 ⬇️ 这里很明显有一个gap： 核武器测试的次数增加是否能导致人们感受到更多的核灾难的威胁 如果： 核武器测试的次数 ⬆️ ➡️ 感受到和灾难威胁 ⬆️ ✅原文的逻辑论证就是对的 核武器测试的次数 ⬆️ 不能让人们 感受到和灾难威胁 ⬆️ ❌原文的逻辑论证就是错的 所以很明显原文逻辑论证的additional premise是：核武 器测试的次数 ⬆️ ➡️ 感受到和灾难威胁 ⬆️ 所以选择C
小前提结论型文章
🔴中文例子
Premise：如果小明是女孩，178cm的身高超过了98%的人； Conclusion：小明身高很高； 这个论述要比上面的题目更复杂一些，多了一个小前提 ✅大前提 所以如果想要这个逻辑论证成立的前提是： 小明是女生，如果不是，就不能得出结论小明身高很高了；
🔻具体题目 A decrease in face-to-face social contact can precipitate depression. Time spent using the Internet cannot be spent in face-to-face social contact, so psychologists have speculated that sharply increasing Internet use can cause depression. Studies of regular Internet users have found a significantly higher incidence of depression among those who had recently doubled the amount of time they spent using the Internet than among those whose use had not increased. Hence, the psychologists’ speculation is correct.
⛳️Which of the following is an assumption on which the argument depends?
A. In general, the reason that the people in the studies had doubled their Internet use was not that they had earlier experienced a significant decrease in opportunities for face-to-face social contact. B. A sharp decrease in face-to-face social contact is the only change in daily activity that can lead to an increased incidence of depression. C. Using the Internet presents no opportunities for people to increase the amount of face-to- face social contact they experienced in their daily lives. D. Regular Internet users who are depressed will experience an immediate improvement in mood if they sharply decrease the amount of time they spend on the Internet. E. Before they doubled the time they spent on the Internet, the people who did so were already more prone to depression than are regular Internet users in general.
原文逻辑论证思路
Premise：上网时间 ⬆️ ➡️ 面对面社交 ⬇️ ➡️ 抑郁 Conclusion：上网时间 ⬆️ ➡️ 抑郁
🔻整篇逻辑论证的思路是
前提： 增加上网时间 ➡️ 减少面对面 ➡️ 抑郁 结论： 增加上网时间 ➡️ 抑郁 但是有可能小前提：上网时间的增加并不一定会导致面对面社交的减少。
原文中只说的是上网的时间不能用在面对面社交上，原文的推理确实上网增加一定会导致面对面社交的减少（比如，线下网友见面会，这是因为网上时间的增加导致的面对面社交的增加的例子），这样的话，原文的逻辑论证就不成立了。
所以如果想支持原文的逻辑论证，我们需要确保小前提是对的：增加上网时间不会导致面对面社交的增加，因此答案选择C
🔻练习题目
Metropolis regulation limiting to four days the period during which milk can be sold to consumers after pasteurization is unreasonable. Under optimal conditions, pasteurized milk kept at 40 degrees Fahrenheit remains unspoiled for at least 14 days. If Metropolis current limitation were changed to eight days, milk prices would drop, but product quality would be unaffected.
⛳️Which of the following, if true, would most seriously weaken the conclusion drawn above?
A.Most consumers keep milk no more than three days after purchase. B.A recent survey showed that 20 percent of Metropolis consumers favored extending the current limitation on the sale of milk to 8 days. C.Metropolis' grocery-store owners would prefer small, frequent deliveries of milk to larger, infrequent deliveries. D.Milk kept longer than 14 days after pasteurization generally presents no medical dangers if consumed. E.In Metropolis, conditions for handling and storing milk after pasteurization are seldom close to optimum
原文逻辑论证思路
前提：完美的情况下--牛奶14天不变质 结论：如果改为8天，价格会下降&质量不受影响
🔻这里有一个小前提： 如果没有完美情况，就没办法满足题目中的前提：14天不变质了 所以削弱的话可以懂小前提出发； ✅所以答案选择：D，没有完美情况
下期我们会讲解另外一个文章结构：现象解释型文章的解题思路，敬请期待！
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