大全testB-2

2.     In the years since the city of London imposed strict air-pollution regulations on local industry, the number of bird species seen in and around London has increased dramatically. Similar air-pollution rules should be imposed in other major cities.

Each of the following is an assumption made in the argument above EXCEPT:

(A) In most major cities, air-pollution problems are caused almost entirely by local industry.

(B) Air-pollution regulations on industry have a significant impact on the quality of the air.

(C) The air-pollution problems of other major cities are basically similar to those once suffered by London.

(D) An increase in the number of bird species in and around a city is desirable.（A）

(E) The increased sightings of bird species in and around London reflect an actual increase in the number of species in the area.

why choose A?  I choose D.

Thanks for replying.

我是这么理解的：

except 表明：如果选项不……，结论也能成立

A 大多数城市里，空气污染问题几乎完全是由当地工业造成的

如果不是完全由工业造成，其他一些问题也会造成污染，但只要工业会污染空气，就需要有执行相关政策，这样至少可以增加一点鸟的数量。

D 希望在城市里或城市周围增加鸟的数量。

如果不希望增加鸟的数量，那也不需要采取相关政策控制空气污染了。结论就不成立了。

不知讲的对不对，共同探讨

本推理的结论是Similar air-pollution rules should be imposed in other major cities, 其依据是London imposed stritct air-pollution regulations on local industry从而导致London周围的鸟类（可见的）数量增加。推理方法用到了类比，london 和其他城市，以及imposed stritct air-pollution regulations on local industry和鸟类（可见的）数量增加的因果关系，但没有涉及其它城市的污染的原因是almost entirely by local industry or not.

所以A和本题无关

好象很多人问这题啊    在太傻上也看到过这个题目。