Most scientists seem to agree that certain limit should be set on sale of cars to ease ai

问题补充：

Most scientists seem to agree that certain limit should be set on

sale of cars to ease air pollution.

A. a; the

B. /; the

C. the; /

D. the; the

答案：

(答案→)A. a; the

B. /; the

C. the; /

D. the; the

解析：考察冠词。本题第一空使用a泛指一个限制。第二空使用the特指汽车的销售。句意：大部分科学家都同意为了减少空气污染，我们要设立一个限制来限制汽车的销售。故A正确。