| 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. 这题选A， In most major cities, air-pollution problems are caused almost entirely by local industry. 我觉着不能理解：如果air-pollution problems are not coused by local industry, 那有关的air-pollution regulations on local industry就不是the quality of air became better的原因了，那这个argument就不成立了阿？？难道是因为“almost entirely”导致程度太强了？或太弱了？还是其他原因呢？ 另外，argument 的assumption应该是它的必要而非充分条件吧？
请好心高手指教啊！ | 
