虽然之前的回应不好...但不管三七二十一先把这个也放上来了...给希望从基础入手的同学，大家都加油！
Assumption - 假设是作者没有在文章中提到，但确信为真，并帮助推出结论的东西。（注：假设不一定在现实世界中也是真的）
如：That car is green. Therefore, that car cannot belong to Dan. 那辆车是绿的-> 车肯定不是Dan的 假设：Dan没有绿色的车 全文变为：那辆车是绿的-> Dan没有绿色的车-> 车肯定不是Dan的
再如：Amy got an A on the test. Therefore, Amy must have studied for along time. 所以作者的结论是Amy一定学习了很长的时间，而且这是可以得A的唯一方法。 假设要填补论述中的Gap：长时间学习是得A的唯一办法。 - 大部分的GMAT论述会包括多个假设。所以做假设题时有下面三做三不做。
Do 头脑风暴你能想出的简单的假设 Don’t 不要花超过20秒时间做这件事 Do 寻找你头脑风暴时想到的假设 Don’t 不要因为不符合你预想的假设而删除选项 Do 寻找作者认为一定是对的，并由此推导出结论的东西 Don’t 不要只关注让结论“完美”或绝对真实的东西（即文章有多个假设，选项只涉及了一个，可能我们觉得还应该有其他的假设才完整，但也不用纠结于此） The employees of Quick Corp’s accountingdepartment consistently show a significant jump in productivity in the twoweeks before taking vacation. Clearly, the knowledge that they are about to goon vacation motivates the employees to maximize their productivity. 逻辑链：放假前两个星期员工生产力大幅度提升-> 知道要放假可以最大化员工的生产力 假设：论述中有几个假设：首先前提只提到“大幅度提升”，并没有说明是最大化的生产力，因此可以说作者假设了“大幅度提升”代表了最大化的生产力； 另外，作者说员工决定更有生产力是因为知道自己要放假，因为也许还有一种情况，是因为他们只是选工作量增大之后才放假？但作者假设不是这种情况，所以员工并不是选择忙季之后放假，而是得知要放假后提升了生产力（好严谨…把英文解释附在这里，以免我翻译的不到位：The author concludes that employees decide to be more productivebecause they’ll be taking vacation soon. Perhaps it’s the case, instead, thatthe employees choose to take vacation right after they know they’ll be forcedto work harder for some other reason. This author is assuming that this is NOTthe case—that employees are NOT choosing to take vacation after what theyknow will be a busy time at work.） When news periodicals begin forecasting arecession, people tend to spend less money on non-essential purchases（前提，杂志预测不景气，人们就减少非必需品花费）. Therefore, the perceived threat of a future recession decreasesthe willingness of people to purchase products that they regard as optional or luxurygoods（结论，解释减少花费的原因，感觉到未来的威胁）. Which of the following is an assumption onwhich the argument depends? A) People do not always agree asto which goods should be considered luxury goods.（和结论不相关） B) People are more likely to haveread a news periodical recently because more and more periodicals are beingpublished.（不十分相关） C) Most people do not regularlyread news periodicals.（方向恰好相反） D) The consumer perception of thethreat of recession increase when news periodicals begin forecasting arecession.（杂志开始预测，人们感受到威胁，花钱变少，正确） E) At least some of thebiggest-spending consumers prior to the recession were among those whocurtailed their spending after the recession began.（after therecession，超出讨论范围） - 将备选答案取非（这个在很多逻辑方法中都已经陈述过了。但注意：由于需要较多时间，因此要在最后两个选项抉择时才用这个方法。）
因为假设是作者必须相信是真的的陈述，所以如果我们取非的话，作者的论述就会遭受到削弱。 如上面杂志预测经济不景气的例题（逻辑链是：前提，杂志预测不景气，人们就减少非必需品花费；结论，解释减少花费的原因，感觉到未来的威胁）。可以将选项B和选项D取非，进一步确定答案。 B) Peopleare more likely to have read a news periodical recently because more and moreperiodicals are being published. D) Theconsumer perception of the threat of recession increase when news periodicalsbegin forecasting a recession. B选项取非为People are NOTmore likely to have read a news periodical recently and more periodicals areNOT being published.杂志没有更多地发行并没有削弱相关结论 D选项取非为 The consumerperception of the threat of recession DOES NOT increase when news periodicalsbegin forecasting a recessing.如果杂志预测萧条但消费者没有感受到，就无法做出因为感受到威胁才减少花费的结论，正确。 摘抄Lawyer关于假设题如何取非的内容，加深一下大家的记忆： 1. all----not all/some---none/always----notalways/sometimes----never/everywhere---not everywhere/somewhere---nowhere/onlyone, exactly one---none, more than one/at least one, some---none 2. 对于选项为条件句，将必要条件取非。 3. 直接将谓语肯定变否定，或否定变肯定。 但是切记，不可以直接取非A推出非B。 如PREP08上的例题
Newspapereditorial: In an attempt to reduce the crime rate, the governor is getting tough on criminals and making prisonconditions harsher. Part of this efforthas been to deny inmates the access they formerly had to college-levelcourses. However, this action is clearlycounter to the governor's ultimate goal, since after being released fromprison, inmates who had taken such courses committed far fewer crimes overallthan other inmates. Which of the following is an assumption on which the argument depends? A. Not being able to take college-level courseswhile in prison is unlikely to deter anyone from a crime that he or she mightotherwise have committed. B. Formerinmates are no more likely to commit crimes than are members of the generalpopulation. 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 release D.Taking high school level courses in prison has less effect on an inmate'ssubsequent behavior than taking college-level courses does. E.The governor's ultimate goal actually is to gain popularity by convincingpeople that something effective is being done about crime. 正确答案C。逻辑链：前提，为了减低犯罪率，政府决定不给犯人读书的机会恶化监狱环境，结论，这样起反效果，犯人读书后更少犯罪。答案C排除他因。 迷惑答案A中，不能直接用非A推出非B。
- 超出范围out of scope（答案没有联系结论）
- 用了相反的逻辑（答案削弱了论述，没有增强）
- 作了不相关的比较
书后练习题
1. For several year, Nighttime News attracted fewer viewers than World News, which broadcasts its show at the same time as Nighttime News. Recently, the producers of Nighttime News added personal interest stories and increased coverage of sports and weather. The two programs now have a roughly equal number of viewers. Clearly, the recent programming changes persuaded viewers to switch from World News to Nighttime News.
The conclusion above is properly drawn if which of the following is assumed?
A) Viewers are more interested in sports and weather than in personal interest stories.
B) The programming content of Nighttime News is more closely aligned with the interests of the overall audience than is the content of World News
C) Some World News viewers liked the new Nighttime News programming better than they liked the World News programming.
D) There are other possible causes for an increase in the number of viewers of Nighttime News, including a recent ad campaign that aired on many local affiliates.
E) The quality of World News will remain constant even if Nighttime News improves.
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正确答案C
For several year, Nighttime News attracted fewer viewers than World News, which broadcasts its show at the same time as Nighttime News. Recently, the producers of Nighttime News added personal interest stories and increased coverage of sports and weather. The two programs now have a roughly equal number of viewers（前提，NN观众数一直追不上WN，NN改版加入三个新节目，观众数差不多了）. Clearly, the recent programming changes persuaded viewers to switch from World News to Nighttime News（结论，新节目将观众从一个节目吸引到另一个）.
从以上我们可以联想到的假设有：NN的观众数上升，WN的观众数下降，而WN流失的观众都转向了NN—也就是说他们没有去看新节目，也没有彻底不看电视。
A) Viewers are more interested in sports and weather than in personal interest stories.（是NN改版后三个节目内部对比，无意义）
B) The programming content of Nighttime News is more closely aligned with the interests of the overall audience than is the content of World News.（取非后没有更closely和观众兴趣匹配，那有可能两个节目差不多水平，不削弱结论 ）
C) Some World News viewers liked the new Nighttime News programming better than they liked the World News programming.（取非，没有WN的观众更喜欢NN的节目，那为什么换台？削弱，正确）
D) There are other possible causes for an increase in the number of viewers of Nighttime News, including a recent ad campaign that aired on many local affiliates.（只讨论三个节目新变化，不考虑other possible causes）
E) The quality of World News will remain constant even if Nighttime News improves.（不一定要为真）
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2. Two genes, BRCA1 and BRCA2, and linked to hereditary breast cancer. Therefore, in order to decrease the annual number of mammogram tests administered across a population and to more accurately assess a woman's individual risk of breast cancer, all women should be tested for these genes.
Which of the following is an assumption on which the argument depends?
A) Some of the women who are tested for the two genes will subsequently undergo mamograms on a less frequent basis than they used to
B) The majority of breast cancer patients have no family history of the disease.
C) Researchers may have identified a third breast cancer gene that is linked with hereditary breast cancer.
D) Women who have these genes have an 80 percent chance of getting breast cancer, while women who do not have these genes have only a 10 percent chance of getting breast cancer
E) The presence of BRCA1 and BRCA2 can explain up to 50 percent of hereditary cases.
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正确答案为A
Two genes, BRCA1 and BRCA2, and linked to hereditary breast cancer. Therefore, in order to decrease the annual number of mammogram tests administered across a population and to more accurately assess a woman's individual risk of breast cancer, all women should be tested for these genes.（作者鼓励test基因因为两个原因：降低Mtest的数量，以及更好的监测风险）
A) Some of the woman who are tested for the two genes will subsequently undergo mamograms on a less frequent basis than they used to（哪怕只是some，也可以帮助Mtest的数量下降，正确）
B) The majority of breast cancer patients have no family history of the disease.（削弱了结论）
C) Researchers may have identified a third breast cancer gene that is linked with hereditary breast cancer.（和文章无关）
D) Women who have these genes have an 80 percent chance of getting breast cancer, while women who do not have these genes have only a 10 percent chance of getting breast cancer.（是否一定为真？不一定，也许是70%或90%替代了数据，结论仍然为真）
E) The presence of BRCA1 and BRCA2 can explain up to 50 percent of hereditary cases.（有具体数字，和上一个选项一样，不一定为真）
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还有另一个关于BF题和结构题的帖子，链接如下，供参考：
【入门级】Manhattan BF题和结构题中文总结笔记及Manhattan练习题—适合初学者
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发表于 2013-7-5 22:56:46
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