GWD5-Q38 求助

bmr19910516

Nitrogen dioxide is apollutant emitted by automobiles. Catalytic converters, devices designed to reduce nitrogen dioxideemissions, have been required in all new cars in Donia since 1993, and as aresult, nitrogen dioxide emissions have been significantly reduced throughoutmost of the country.  Yet although theproportion of new cars in Donia’s capital city has always been comparativelyhigh, nitrogen dioxide emissions there have showed only an insignificantdecline since 1993.
Which of thefollowing, if true, most helps to explain the insignificant decline in nitrogendioxide emissions in Donia’s capital city?


A.   More of the cars in Donia’s capital citywere made before 1993 than after 1993.
B.   The number of new cars sold per year inDonia has declined slightly since 1993.
C.   Pollutants other than nitrogen dioxide thatare emitted by automobiles have also been significantly reduced in Donia since1993.
D.   Many Donians who own cars made before 1993have had catalytic converters installed in their cars.
E.    Most car trips in Donia’s capital city aretoo short for the catalytic converter to reach its effective workingtemperature.
这道题我选的D，如果Donian的居民早在1993年之前就用上这个转换器的话，在1993年之前nitrogen dioxide emissions就已经显著下降了。所以1993年有了正式法律规定之后，相较于之前几年的数据并不会有太大下降。题目只说了这个法规是1993年新出台的，没说这个发明是最近研究出来的，所以没有和题干违背的地方。
反倒是E看着就像典型陷阱选项....Most car这个说法肯定都是指已经有的汽车，他们的工作温度有问题不代表新买的车也一定有同样的问题。
以上是我的疑问，求大牛解释...ps这是我这套题唯一错了的，到现在也不明白怎么回事...

cdwayne

Hi, your explanation of (D) is out of scope, because it doesn't apply to the new cars, which are always comparatively high but contribute to little than expectation.

(E), although it refers to most cars, but it is also applicable especially to the new ones.