In the nation of Partoria, large trucks currently account for 6 percent of miles driven on Partoria’s roads but are involved in 12 percent of all highway fatalities.The very largest trucks—those with three trailers（拖车，挂车）—had less than a third of the accident rate of single- and double-trailer trucks.Clearly, therefore, one way for Partoria to reduce highway deaths 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. 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.
B. So far only the best, most experienced drivers for Partorian trucking companies have been driving triple-trailer trucks.
C. Very few fatal collisions involving trucks in Partoria are collisions between two trucks.
D. In Partoria, the safety record of the trucking industry as a whole has improved slightly over the past ten years.
E. In Partoria, the maximum legal payload（装载量） of a triple-trailer truck is less than three times the maximum legal payload of the largest of the single-trailer trucks.
我选的E,现在理解了装载量是无关词，因为题目说的我是事故率的高低和3T卡车的使用。。可是为什么B对啊？ NN们请帮忙解释一下~ 不胜感激作者: zafteria 时间: 2010-9-10 19:58
B项，明显的削弱项。 意思是说：triple-trailer truck 安全的原因是因为most experienced drivers 所以require shippers to increase their use of triple-trailer trucks 这个措施达不到reduce highway deaths 的目的 因为most experienced drivers 的数量是有限的 E项，没有表明措施达不到，只表示运载量不高作者: jessiecg 时间: 2010-9-10 22:11
O(∩_∩)O哈哈 明白了 谢谢牛人