问题补充:
The problem of air pollution is becoming more serious the increasing number of cars.
A. as for
B. because
C. as a result
D. as a result of
答案:
A. as for
B. because
C. as a result
(答案→)D. as a result of
解析:本题的含义为由于车子数量急剧增加的结果,空气污染的问题变得更加严重,as a result of 表示由于……的结果的含义,故本题选D。