求解。所谓sufficient assumption和necessary assumption的问题。

jianaozhonghua

assumption题究竟应该怎么做呢？ 有感觉时候还好 没感觉，一头雾水啊

48. If the county continues to collect residential trash at current levels, landfills will soon be overflowing and parkland will need to be used in order to create more space. Charging each household a fee for each pound of trash it puts out for collection will induce residents

to reduce the amount of trash they create; this charge will therefore protect the remaining county parkland.[c1]

Which of the following is an assumption made in drawing the conclusion above?

This is a necessary?

(A)[c2] Residents will reduce the amount of trash they put out for collection by reducing the number of products they buy.

(B) The collection fee will not significantly affect the purchasing power [c3]of most residents, even if their households do not reduce the amount of trash they put out.

(C)[c4] The collection fee will not induce residents to dump their trash in the parklands illegally.C

(D) The beauty of county parkland [c5]is an important issue for most ofthe county’s residents.

(E)[c6] Landfills outside the county’s borders could be used as dumping sites for the county’s trash.

[c1]条件型结论



[c2]无关



[c3]无关



[c4]排除充分条件出现，必要条件不出现



[c5]无关



[c6]无关

题目解释都有了。
不清楚，什么事充分假设必要假设？   看了sdcar那么多帖子只有这里看不懂。   求NN指教！  以及如果使用negate方法做assumption，同求指教！  谢谢了

cutelotus

我发现，只要这样做，题目就好做很多：Assuming the collection fee will not induce the resident to dump the trash in the parklands illegally, then charging each household a fee for each pound of trash is effective.   就是将假设的情况带入句子就OK

cai808

Negate方法只能用作necessary assumption的题目，sufficient assumption就不行

48. If the county continues to collect residential trash at current levels, landfills will soon be overflowing and parkland will need to be used in order to create more space. Charging each household a fee for each pound of trash it puts out for collection will induce residents to reduce the amount of trash they create; this charge will therefore protect the remaining county parkland.

Which of the following is an assumption made in drawing the conclusion above?

Conclusion: protect the remaining county parkland
Assumption: If the county continues to collect residential trash at current levels, landfills will soon be overflowing and parkland will need to be used in order to create more space
Premise:  Charging each household a fee for each pound of trash it puts out for collection will induce residents to reduce the amount of trash they create


(A) Residents will reduce the amount of trash they put out for collection by reducing the number of products they buy. 错

(B) The collection fee will not significantly affect the purchasing power of most residents, even if their households do not reduce the amount of trash they put out.

(C) The collection fee will not induce residents to dump their trash in the parklands illegally.

(D) The beauty of county parkland is an important issue for most of the county’s residents.错

(E) Landfills outside the county’s borders could be used as dumping sites for the county’s trash.错

ABDE显然是错的 因为文章里没有提及
根据http://lsatblog.blogspot.com/2009/11/difference-necessary-sufficient.html给出的解释
这题是sufficient assumption
所以negation test不适用
看了国外的朋友给的解释如下：

(A) Residents will reduce the amount of trash they put out for collection by reducing the number of products they buy. - This can be valid , however low number of products does not necessarily translate in to less trash

(B) The collection fee will not significantly affect the purchasing power of most residents, even if their households do not reduce the amount of trash they put out. - not related as there is no discussion on purchasing power
(C) The collection fee will not induce residents to dump their trash in the parklands illegally.
This looks most valid
(D) The beauty of county parkland is an important issue for most of the county’s residents.
- not related
(E) Landfills outside the county’s borders could be used as dumping sites for the county’s trash.
- If landfills outside the country borders can be used then this will solve the problem and there is no need for charge