OG-77

joywzy

A certain mayor has proposed a fee of five dollars per day on private vehicles entering the city, claiming that the fee will alleviate the city’s traffic congestion. The mayor reasons that, since the fee will exceed the cost of round-trip bus fare from many nearby points, many people will switch from using their cars to using the bus.
Which of the following statements, if true, provides the best evidence that the mayor’s reasoning is flawed?
(A) Projected increases in the price of gasoline will increase the cost of taking a private vehicle into the city.
(B) The cost of parking fees already makes it considerably more expensive for most people to take a private vehicle into the city than to take a bus.
(C) Most of the people currently riding the bus do not own private vehicles.
(D) Many commuters opposing the mayor’s plan have indicated that they would rather endure traffic congestion than pay a five-dollar-per day fee.
(E) During the average workday, private vehicles owned and operated by people living within the city account for twenty percent of the city’s traffic congestion.

答案:B,A为何不是削弱啊?谢谢.

joywzy

up.

请大家帮助.

xiang_y

There is a hidden assumption in Mayor's line of reasoning: Whether people drive their own car or take bus is depend on the cost. If people think cost is too high for driving their own car, they will switch to bus.

To point out the flaw in the argument, you need find evidence to attack this assumption. If what B said is true, then cost is not the cause for people's decision, which make the above assumption no longer hold. Answer A only states a fact, has no effect on the line of reasoning. Why you choose A?

joywzy

我认为A的道理和B 一样.假设是人们会关心cost,A:汽油价格的上升,增加了人们开车进城的费用.这说明开车进城的人,他们要开车,并不是太关心价格.所以否定了假设啊.

xiang_y

以下是引用joywzy在2003-11-20 17:58:00的发言：
我认为A的道理和B 一样.假设是人们会关心cost,A:汽油价格的上升,增加了人们开车进城的费用.这说明开车进城的人,他们要开车,并不是太关心价格.所以否定了假设啊.

A 只告诉你“汽油价格的上升,增加了人们开车进城的费用”这个将要发生的事，并没有告诉你如果发生后，人们是不是还要开自己的车。

joywzy

那么B呢?

B讲到了停车费使开车人开车的成本更高了.

我主要是晕在A与B上.感觉两个一样的.为何A不好?

xiang_y

以下是引用joywzy在2003-11-20 18:20:00的发言：
那么B呢?

B讲到了停车费使开车人开车的成本更高了.

我主要是晕在A与B上.感觉两个一样的.为何A不好?

OK， B中“The cost of parking fees already makes it considerably more expensive ”，注意 already, 说明parking fees is expensive是一个继成事实， 可今天大家还是开自己的车， 这说明了people 对cost 的态度。 而A中"increases in the price of gasoline will increase the cost", 注意 will, 这是将来要发生的事， 发生之后people 会怎样并没说，你不能assume people will still drive their own car.

joywzy

明白啦,我就是这个糊涂了.谢谢xiang_y

BetterMan

正好我也有些小疑惑, 请教一下.
答案D中的Commuter指的是做Bus的呢? 还是本来开 Car的?
D的逻辑角度是什么?

xiang_y

Commuters in D are the people who drive their own car.

D 是一个迷惑选项。 如果题目问哪个选项消弱市长计划的可行性， D maybe right.
However, the question ask you to find the flaw in mayor's reasoning. Then whether commuter agree or disagree the plan won't point out the flaw. Further more, if commuter would rather endure traffic congestion than pay a five-dollar-per day fee,  it means they are very concern about the increase cost, which supports the mayor's assumption mentioned above.