有关干扰选项

总结的时候，有点疑惑。比如A--->B， 其他具有/不具有A特征的东东是否能导致B，不能support或者weaken 原arguement的

例如：OG137 ，原文逻辑是couple have unhappy marriage－－》睡眠周期不一致

weaken 很经典，说是睡眠周期不一致－－》couple have unhappy marriage其中有一个选项，其他couple 睡眠周期一致也会导致unhappy marriage ，排除，不能weaken

同例，忘了是OG还是补充材料了。说人们害怕bat－－－》bat 夜里活动

也是问weaken ，好像答案是  wolf什么的东西也是夜里活动，但是人门不害怕

再例

A law requiring companies to offer employees unpaid time off to care for their children will harm the economic competitiveness of our nation’s businesses. Companies must be free to set their own employment policies without mandated parental-leave regulations.

Which of the following, if true, would most seriously weaken the conclusion of the argument above?

(A) A parental-leave law will serve to strengthen the family as a social institution in this country.

(B) Many businesses in this country already offer employees some form of parental leave.

(C) Some of the countries with the most economically competitive businesses have strong parental-leave regulations.

(D) Only companies with one hundred or more employees would be subject to the proposed parental-leave law.（C）

(E) In most polls, a majority of citizens say they favor passage of a parental-leave law.

C

why？叩谢啊！有NN来帮帮忙吗？非常疑惑！！！！

判断的原则是：对于A -> B,

可以加强的形式有：

（1）A有效并保持；（2）B可能；（3）~A -> ~B (否命题型加强)；（4）A -> B （原文改写型加强）

可以削弱的形式有：

（1）A无效或已不保持；（2）B不可能；（3）B -> A (因果关系颠倒型削弱)；（4）A -> ~B (否定结论型削弱)

其它形式都不构成加强或削弱。对照你找到的所有例子，看看是不是已经非常清楚了。

逆否命题支持原命题没错，只是其与(A->B)等价，没有另外分类。逆否命题而且还是原命题的假设条件。

单纯否命题作为加强题答案的例子很多，比如：

A certain stain of bacteria was found in the stomachs of ulcer  patients. A medical researcher with no history of ulcers inadvertently  ingested  some of the bacteria and within weeks developed an ulcer. Therefore, it is highly likely that the bacteria strain induces ulcers.

Which one of the following, if true, most supports the argument above?
(A) People who have the bacteria strain in their stomachs have been found to have no greater incidence of kidney disease that do people who lack the bacteria strain.
(B) The researcher did not develop any other serious health problems within a year after ingesting the bacteria strain.
(C) There is no evidence that the bacteria strain induces ulcers in laboratory animals.
(D) The researcher is a recognized expert in the treatment of diseases of the stomach.
(E) A study of 2000 people who do not have ulcers found that none of these people had the bacteria strain in their stomachs.

Eight years ago hunting was banned in Greenfield County on the grounds that hunting endangers public safety. Now the deer population in the county is six times what it was before the ban. Deer are invading residential areas, damaging property and causing motor vehicle accidents that result in serious injury to motorists. Since there were never any hunting-related injuries in the county, clearly the ban was not only unnecessary but has created a danger to public safety that would not otherwise exist.

Which one of the following, if true, provides the strongest additional support for the conclusion above?
(A) In surrounding counties, where hunting is permitted, the size of the deer population has not increased in the last eight years.
(B) Motor vehicle accidents involving deer often result in damage to the vehicle, injury to the motorist, or both.
(C) When deer populations increase beyond optimal size, disease and malnutrition  become more widespread among the deer herds.
(D) In residential areas in the county, many residents provide food and salt for deer.
(E) Deer can cause extensive damage to ornamental  shrubs  and trees by chewing on twigs and saplings.

自己做做答案是哪个吧。

第一题我选E。结论是：菌种导致胃溃疡（A-〉Ｂ），Ｅ是没有胃溃疡就没有发现菌种　（～Ｂ－〉～Ａ）

第二题我选Ａ。结论是：禁止捕猎导致鹿群增大以至影响公共安全（Ａ－〉Ｂ），Ａ是允许捕猎的地方，鹿群在过去８年中没有增长过　（～Ａ－〉～Ｂ），用来排除其他可能，说明Ａ是导致Ｂ的唯一原因。

谢谢ｇｇ，请查收我的作业。

都对。