求问两道没有弄明白的逻辑题

liaonotliao

1.In 1992 outlaw fishing boats began illegally harvesting lobsters from the territorial waters of the country of Belukia. Soon after, the annual tonnage of lobster legally harvested in Belukian waters began declining; in 1996, despite there being no reduction in the level of legal lobster fishing activity, the local catch was 9,000 tons below pre-1992 levels. It is therefore highly likely that the outlaw fishing boats harvested about 9,000 tons of lobster illegally that year.

Which of the following is an assumption on which the argument depends?

(A) The illegal lobster harvesting was not so extensive that the population of catchable lobsters in Belukia’s territorial waters had sharply declined by 1996.

(B) The average annual lobster catch, in tons, of an outlaw fishing boat has increased steadily since 1992.

(C) Outlaw fishing boats do not, as a group, harvest more lobsters than do licensed lobster-fishing boats.

(D) The annual legal lobster harvest in Belukia in 1996 was not significantly less than 9,000 tons.

(E) A significant proportion of Belukia’s operators of licensed lobster-fishing boats went out of business between 1992 and 1996.
这道题答案选a 我可以理解 但是我始终无法理解为什么e是错误答案
1992 1993 1994 1995 1996 这五年里, 根据题干 非法fishing一直都有,  而我们无法知道是否legal fishing是否在这五年里 年年都存在
根据题干 in 1996, despite there being no reduction in the level of legal lobster fishing activity只能推出 1996这一年合法捕鱼的活动存在 而且活动数量没有减少 所以才会有 捕鱼量比1992前少 9000吨 这么一个 surprising finding.  无法得知是否1992-1995一直都有合法捕鱼活动
如果在 1992 1993 1994 1995里没有合法捕鱼量 则原文结论尚可
如果有捕鱼量的话 那1992非法捕鱼的量就不可能是9000吨啊? 因为这样既有 合法捕鱼量 也有 1993到1995期间非法捕鱼量两个变量 怎么可能推出1992非法捕鱼量就一定是9000吨呢?


2.In the year following an eight-cent increase in the federal tax on a pack of cigarettes, sales of cigarettes fell ten percent. In contrast, in the year prior to the tax increase, sales had fallen one percent. The volume of cigarette sales is therefore strongly related to the after-tax price of a pack of cigarettes.

The argument above requires which of the following assumptions?

(A) During the year following the tax increase, the pretax price of a pack of cigarettes did not increase by as much as it had during the year prior to the tax increase.

(B) The one percent fall in cigarette sales in the year prior to the tax increase was due to a smaller tax increase.

(C) The pretax price of a pack of cigarettes gradually decreased throughout the year before and after the tax increase

(D) For the year following the tax increase, the pretax price of a pack of cigarettes was not eight or more cents lower than it had been in the previous year.

(E) As the after-tax price of a pack of cigarettes rises, the pretax price also rises.

oa

还有这道题 完全不懂 没思路 网上查解析也是五花八门....请大神指导
谢谢!

liaonotliao

第二题oa 是 d选项

老白在费城

第一题：题目说的是：96年合法捕鱼数比92年少了9000吨。题目的结论是：所以少的9000吨一定是非法的人捕去了。题目问的是：得出这个结论需要什么前提一定成立。
分析：选项E说的是：大量合法渔船在92-96年间不干了。那么如果E成立，那么96年的合法捕鱼数自然比92年少，根本不能得出“少的9000吨一定是非法的人捕去了”的结论。所以想要得出这个结论，E肯定不能成立。所以E肯定错。

第二题：题目说的是：烟草税涨了8分钱的第二年，销售降了10%。而涨之前，销售只降了1%。题目的结论是：所以烟草的销售是和税后价格强烈有关的。
分析：如果要得出这个结论，那么假设就是烟草税后价格越高，销售越下降。但是题目只提到了税的上涨，并没有提到原价的变化，而税后价格取决于税+原价。所以想要得出题目的结论，前提就是，原价不能跌超过8分钱。因为如果跌超过8分钱的话，烟草的税后价格反而比之前低了，那么税后价格低了，销售还低，题目的结论就不成立了。

做这种前提类型的题目，正确的答案一定是：结论成立，正确答案里提到的条件一定要成立；如果正确答案里提到的条件不成立，那么题目里的结论也肯定无法成立。

liaonotliao

谢谢楼上！

Bensontuo

老白在费城 发表于 2019-4-20 11:33
第一题：题目说的是：96年合法捕鱼数比92年少了9000吨。题目的结论是：所以少的9000吨一定是非法的人捕去了 ...

費城老白講得很好, 但是有另外一個方法可以幫助樓主更快解題。

首先, 題目專注的群體在於 - 非法捕魚的人一定得為那少補的九千噸負責任, 然後, 這題是問必要假設, 何為必要假設呢？  就是一個前體的存在必需要gurantee.

我們來看Ｅ選項, 少補的九千頓如果是因為合法漁船變少了, 那就可能代表這九千頓可能還在海裡面跟派大星玩耍, 而不是在非法捕魚船的船上, 所以Ｅ選項反而是削弱了本文邏輯。

liaonotliao

谢谢大家！

小可爱的小可爱

请问这道题怎么看出是合法捕捞的数目下降了9000，而不是捕捞的总量下降了9000。the local catch was 9,000 tons below pre-1992 levels, local catch 指总量是不是也读得通。如果按照合法量下降9000，假设总数不变，那也只能推出非法量增加9000，而不是非法量就是9000啊。