171. A recent report determined that although only three percent of drivers on Maryland highways equipped their vehicles with radar detectors, thirty-three percent of all vehicles ticketed for exceeding the speed limit were equipped with them. Clearly, drivers who equip their vehicles with radar detectors are more likely to exceed the speed limit regularly than are drivers who do not.
The conclusion drawn above depends on which of the following assumptions? (A) Drivers who equip their vehicles with radar detectors are less likely to be ticketed for exceeding the speed limit than are drivers who do not. (B) Drivers who are ticketed for exceeding the speed limit are more likely to exceed the speed limit regularly than are drivers who are not ticketed. (C) The number of vehicles that were ticketed for exceeding the speed limit was greater than the number of vehicles that were equipped with radar detectors. (D) Many of the vehicles that were ticketed for exceeding the speed limit were ticketed more than once in the time period covered by the report. B
(E) Drivers on Maryland highways exceeded the speed limit more often than did drivers on other state highways not covered in the report. 这题小弟对答案有点想不明白 我看完题认为原文第一句给出的是一个现象关系，既3％装雷达的人在被超速罚款的人中占了33％。认为这是一个现象，不是一个因果推理，然后题目第二句就给出了结论认为是装了雷达导致司机更容易超速，认为这是一个因果推论。 分析认为有两种可能，既一种是因为装了雷达导致超速，还有一种可能是因为装雷达的司机本身就更容易超速，他装了超速，不装也超速。装了在33％里，不装这些司机就在67％里。 所以觉得答案应该是排除后一种可能作为假定，应当是：装雷达的司机没有比没有装雷达的司机更容易超速。 可是答案里没有找到，B我没有想明白，而且取非我也没办法削弱原文，请教各位，指点一二。 | 
