求XDJMs解释Prep 2007 CR1 第55题

珍妮弗

According to the Tristate Transportation Authority, making certain improvements to the main commuter rail line would increase ridership dramatically.  The authority plans to finance these improvements over the course of five years by raising automobile tolls on the two highway bridges along the route the rail line serves.  Although the proposed improvements are indeed needed, the authority's plan for securing the necessary funds should be rejected because it would unfairly force drivers to absorb the entire cost of something from which they receive no benefit.

Which of the following, if true, would cast the most doubt on the effectiveness of the authority's plan to finance the proposed improvements by increasing bridge tolls?

(A) Before the authority increases tolls on any of the area bridges, it is required by law to hold public hearings at which objections to the proposed increase can be raised.
(B) Whenever bridge tolls are increased, the authority must pay a private contractor to adjust the automated toll-collecting machines.
(C) Between the time a proposed toll increase is announced and the time the increase is actually put into effect, many commuters buy more tokens than usual to postpone the effects of the increase.
(D) When tolls were last increased on the two bridges in question, almost 20 percent of the regular commuter traffic switched to a slightly longer alternative route that has since been improved.
(E) The chairman of the authority is a member of the Tristate Automobile Club that has registered strong opposition to the proposed toll increase.
为什么不选C？C说commuters会买更过tokens来推迟“the effects of the increase”这样不就会影响authority‘s plan的有效性了吗？答案是D，但是D说只有20%的乘客换到alternative route that has since been improved,如何比较C和D哪个对authority plan的有效性削弱更大啊？求解释，各路NN请分解，谢谢！

treewing929

According to the Tristate Transportation Authority, making certain improvements to the main commuter rail line would increase ridership dramatically.  The authority plans to finance these improvements over the course of five years by raising automobile tolls on the two highway bridges along the route the rail line serves.  Although the proposed improvements are indeed needed, the authority's plan for securing the necessary funds should be rejected because it would unfairly force drivers to absorb the entire cost of something from which they receive no benefit.

Which of the following, if true, would cast the most doubt on the effectiveness of the authority's plan to finance the proposed improvements by increasing bridge tolls?

(A) Before the authority increases tolls on any of the area bridges, it is required by law to hold public hearings at which objections to the proposed increase can be raised.
(B) Whenever bridge tolls are increased, the authority must pay a private contractor to adjust the automated toll-collecting machines.
(C) Between the time a proposed toll increase is announced and the time the increase is actually put into effect, many commuters buy more tokens than usual to postpone the effects of the increase.
(D) When tolls were last increased on the two bridges in question, almost 20 percent of the regular commuter traffic switched to a slightly longer alternative route that has since been improved.
(E) The chairman of the authority is a member of the Tristate Automobile Club that has registered strong opposition to the proposed toll increase.
为什么不选C？C说commuters会买更过tokens来推迟“the effects of the increase”这样不就会影响authority‘s plan的有效性了吗？答案是D，但是D说只有20%的乘客换到alternative route that has since been improved,如何比较C和D哪个对authority plan的有效性削弱更大啊？求解释，各路NN请分解，谢谢！

-- by 会员 珍妮弗 (2012/3/12 12:08:23)

我不太看明白 c, 但後面部份說 postpone, 即是說遲點有效果 (不等如沒有效果)

wwc008love

看看我这样解释对不对，
C的意思是 车主在toll计划实施之前会买很多的票，这样计划实施了用票就可以节约钱。
但是注意，我们要论证的是政府不能通过toll计划筹到钱花在rail way上
票迟早要用完的，用完了还是要花更多钱在过路费上，那计划还是OK的，只是筹钱晚了点
D的话。。虽然只有20%的人改道，但已经削弱了结论的effectiveness...
因为如果20%的人改道了，至少减少了政府筹到足够钱的可能性。BINGO

好难啊这题。。想了好久

珍妮弗

谢谢回复，可是为什么选D呢？20%算是很大比例吗？真心不懂C啊

treewing929

谢谢回复，可是为什么选D呢？20%算是很大比例吗？真心不懂C啊

-- by 会员 珍妮弗 (2012/3/12 12:28:54)

試想想:
政府要收1億元, 這個費用計算當然是靠現在使用量(X) ---->Total=x*$/per
如果將來使用量少了1/5, total 必定不夠.
你不能想1億元是政府會收多!

neo19

你这么想，C虽然推迟了，但是政府可以提高收费啊，计划还是可行的。
但是D直接没人去了，彻底完蛋了。。。。

珍妮弗

okay，C是推迟了有效性，但最终还是要买票的，毕竟此course要five years，买再多的tokens也撑不了5年。而D是减少了20%的客流量，损失上比买tokens更大，而且如果5年内一直都是这个趋势的话，损失比暂时买tokens大多了。想通了！（有时候真觉得逻辑给的答案好勉强）谢谢大家的解释，CDers好强大！大家加油啊，G就是你强它就弱的事儿！

huimousanguo

珍妮弗 发表于 2012-3-12 13:56
okay，C是推迟了有效性，但最终还是要买票的，毕竟此course要five years，买再多的tokens也撑不了5年。而D ...

我开始的想法也是这样的，觉得推迟了也没用，毕竟最后还是要交钱的，但后来仔细一想又觉得不对了。如果司机们可以买一年的票，那么这个五年期的提高收费计划想当于只执行了四年，筹到的钱只会是计划的80%。如果又20%的司机选择走别的路，那么损失的钱是20%，筹到的也是计划的80%，这样的话感觉两种情况的结果是一样的.....
当然也可以假设按照这样的趋势，司机量可能会进一步减少，但是我也可以假设司机们可以买两年的票，甚至三年的都有可能

polaxnic

我觉得C不对的原因就是没说出比例吧，只说了many commuters buy more tokens than usual
所以这个对increase收费的effective是不可知的，可以影响微乎其微也可以影响比较大，
需要其他条件来补充，比如一个人允许买多少，或者token会不会过期之类的。
这题问的是cast most doubt.只有D比较明确 20%已经是significant influence了

polaxnic

huimousanguo 发表于 2015-4-22 01:50
我开始的想法也是这样的，觉得推迟了也没用，毕竟最后还是要交钱的，但后来仔细一想又觉得不对了。如果司 ...

你不能给条件再加附加条件