标题: PREP 78 [打印本页] 作者: elusive 时间: 2016-3-26 06:23 标题: PREP 78 78. In the nation of Partoria, large trucks currently have a much higher rate of traffic accidents per mile driven than other vehicles do. However, the very largest trucks—those with three trailers—had less than a third of the accident rate of single- and double-trailer trucks. Clearly, therefore, one way for Partoria to reduce the number of traffic accidents would be to require shippers to increase their use of triple-trailer trucks.
Which of the following, if true, most seriously weakens the argument?
(A) Partorian trucking companies currently use triple-trailer trucks only for long trips using major highways, which is the safest kind of trip for large trucks.
(B) No matter what changes Partoria makes in the regulation of trucking, it will have to keep some smaller roads off-limits to all large trucks.
(C) Increased use of triple-trailer trucks would mean that large trucks would account for a smaller proportion of all miles driven on Partoria’s roads than they currently do.
(D) In Partoria, the safety record of the trucking industry as a whole has improved slightly over the past ten years.
(E) The volume of truck traffic on Partoria’s highways could be reduced by encouraging shippers to use rail transport whenever possible.
这道题H说是相关因果，因为 largest trucks—those with three trailers—had less than a third of the accident rate of single- and double-trailer trucks. 说了三厢卡车和事故率低有联系
因：因为三厢卡车比和事故率低有联系
果：换三厢卡车。
答案要么说三厢卡车和事故率低有联系，要么给事故率低再说一个解释。
所以是A：事故率低是因为在安全的路上。