标题: gwd中的一道题目 [打印本页] 作者: babydolls 时间: 2011-5-19 17:45 标题: gwd中的一道题目 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. Pollutants 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.
D.不能解释为什么首都与全国不同，只能解释首都有污染 如果题目光说首都怎么多多的新车装了CONVERTER还污染，要选D作者: wwc008love 时间: 2011-5-19 20:54
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. 我看完选的E，俺觉得Donia首都的新车占的比例很大，所以就算1993年的旧车装有converter,排放nitrogen dioxide应该下降的比较明显。 E 提供了另外一个原因支持现象作者: laimanchester 时间: 2011-5-19 22:00
用排除法做吧。首先，要看清楚题目中提到了Donia和Donia首都的情况不同，因而选项就应该解释Donia首都为什么不同（排除bcd）。其次，选项a与题目中所说的矛盾，所以只能选e