GWD-11-20

Q20:

Nitrogen dioxide is a pollutant emitted by automobiles.  Catalytic converters, devices designed to reduce nitrogen dioxide emissions, have been required in all new cars in Donia since 1993, and as a result, nitrogen dioxide emissions have been significantly reduced throughout most of the country.  Yet although the proportion of new cars in Donia’s capital city has always been comparatively high, nitrogen dioxide emissions there have showed only an insignificant decline since 1993.

Which of the following, if true, most helps to explain the insignificant decline in nitrogen dioxide emissions in Donia’s capital city?

A.   More of the cars in Donia’s capital city were made before 1993 than after 1993.

B.   The number of new cars sold per year in Donia has declined slightly since 1993.

C.   ollutants other than nitrogen dioxide that are emitted by automobiles have also been significantly reduced in Donia since 1993.

D.  Many Donians who own cars made before 1993 have had catalytic converters installed in their cars.

E.   Most car trips in Donia’s capital city are too short for the catalytic converter to reach its effective working temperature.

我不明白A，我觉得也对，虽然不如E好。但是逻辑只有对错没有优选的是吧。A：93以前的车太多了，所以也就是没安环保装置的太多，所以氮....化合物才没大量减少的。不知道我这样理解错在什么地方了？？

谢谢

Answer A is controversial stand to the following statement:

Yet although the proportion of new cars in Donia’s capital city has always been comparatively high, ....

N的大部分城市emission显著减少有可能那些城市1993年前的车少，93年后的车多，首都的新车虽然增多不少，但emission降低不明显，说明1993年前的旧车数量多基数大，远远超过新车，所以排放减少当然不明显了。只有A能解释这个现象

我觉得应该选E

A.   More of the cars in Donia’s capital city were made before 1993 than after 1993.说得不够充分，more of并没有说明旧车占据足够大的比例，不足以解释题目

而E的理由相当充分，足够解释为什么新车的装置没发挥作用

any way,非常感谢！！

顶！我还对D 有疑问

D.  Many Donians who own cars made before 1993 have had catalytic converters installed in their cars.

我记得有一个题目很象的。。。就是选的D一样的答案。。。

那位NN帮帮忙啊！

答案是E

http://forum.chasedream.com/dispbbs.asp?BoardID=24&ID=73015