[求助] prep-2-37

37.   (32151-!-item-!-188;#058&006653)

The use of radar detectors in commercial vehicles was banned because commercial truck and bus drivers were using these devices to drive faster than the posted speed limit without fear of arrest.  Since drivers of noncommercial vehicles also use radar detectors and since speeding decreases safety for any vehicle, use of radar detectors should also be banned in noncommercial vehicles to increase safety.

Which of the following, if true, most strongly supports the argument above?

(A) The average noncommercial-vehicle driver is involved in less long-distance driving than is the average commercial-vehicle driver.

(B) In many places airplanes or helicopters are used rather than radar to locate vehicles traveling faster than the posted speed limit.

(C) The ban on radar detectors in commercial vehicles has been effective in deterring them from speeding.

(D) Traffic accidents involving a truck or bus generally pose a greater threat of injury or death than do other accidents.

(E) Radar detectors are sometimes set off by devices other than the law enforcement devices that the radar detectors were built to detect.

请问：这里的set off是什么意思？

我觉得是引发的意思。

btw这题答案是什么呢？

我觉得应该是C

The use of radar detectors in commercial vehicles was banned because commercial truck and bus drivers were using these devices to drive faster than the posted speed limit without fear of arrest.  Since drivers of noncommercial vehicles also use radar detectors and since speeding decreases safety for any vehicle, use of radar detectors should also be banned in noncommercial vehicles to increase safety.

文中给了两个理由，第一个不用说了，第二个说开快车不安全，选项C正好说明了commercial vehicles 的speeding问题，同样适用于noncommercial vehicles，就是结论中的第二个since。

而D所说的不代表一般性，个人觉得是一个special case，不能推广到noncommercial vehicles

Faint…请教各位楼上XDJM选C的原因????..

不好意思这题我懂了

文章表述要支持非商用汽车使用雷达侦测器

就必须由商用汽车有效阻止速度上增加来支持

而D的truck and bus是商用亦或非商用文章未表明所以属无关选项…