GWD7-Q14想不明白为什么E错了！

Certain politicians in the country of Birangi argue that a 50 percent tax on new automobiles would halt the rapid increase of automobiles on Birangi’s roads and thereby slow the deterioration of Birangi’s air quality.  Although most experts agree that such a tax would result in fewer Birangians buying new vehicles and gradually reduce the number of automobiles on Birangi’s roads, they contend that it would have little impact on Birangi’s air-quality problem.

Which of the following, if true in Birangi, would most strongly support the experts’ contention about the effect of the proposed automobile tax on Birangi’s air-quality problem?

1. Automobile emissions are the largest single source of air pollution.

2. Some of the proceeds from the new tax would go toward expanding the nonpolluting commuter rail system.

3. Currently, the sales tax on new automobiles is considerably lower than 50 percent.[C1] 

4. Automobiles become less fuel efficient and therefore contribute more to air pollution as they age.[C2] 

5. The scrapping of automobiles causes insignificant(无意义的，无关紧要的) amounts of air pollution.

多谢LS的，偶明白了··但是我晕了又突然，我觉得D，说“automobile contribute more to airpollution as they age",所以即使“车数量下降了”=》“质量不一定变好”，是个加强选项；但是如果Ｅ改成说＂automobiles causes insignificant amounts of air pollution.”也就是说“其他因素才是造成污染的主要原因”，同样也可以得出“车数量下降了”=》“质量不一定变好”，同样是个加强选项啊！为什么无论automobile contribute more or insignificant  to airpollution 都对原文是个加强选项呢···？～～？偶崩溃了，可能卡在哪了，，请朋友们指点迷津！！！

个人觉得题目的support the contention 是不是应该改成weaken the contention?

        否则答案D显得很奇怪,因为题目问：以下哪个答案支持专家论点，汽车加税对空气污染改善没什么冲击

        可是题目已经说明，政客认为对新车课征新税，有助于减少汽车数量，进而延缓空气污染恶化的问题。
        

这里的思维是，汽车加税造成新车买气减少，进而使汽车增加数量减少，所以可以改善空气质量。

再对照题目所问:哪个答案是支持专家的意见 (汽车加税对空气污染改善没什么冲击)

E认为汽车报废产生的空气污染并不显著。

D认为随着汽车车龄老了，车对于燃料的使用就比较没效率(也就是比较不省油)，也就造成更多空气污染。

A是说汽车放的废气是空气主要的污染源

B是新赋税的部份细则会扩大非污染的通勤铁路系统。

我怎样看,都觉得D是个weaken的答案,请教各位大牛,这里倒底是题目有问题,还是我的思维有错?

        谢谢

Although most experts agree that such a tax would result in fewer Birangians buying new vehicles and gradually reduce the number of automobiles on Birangi’s roads, they contend that it would have little impact on Birangi’s air-quality problem.

注意看这里

车少了，但是旧车多了，所以排放的总量是不会少的

所以即使车少了，污染也不会变少

support