Question

【题目】All the factories are not allowed ______ the harmful gas into the air.

A. releasedB. releaseC. releasingD. to release

Answer 1

【答案】D

【解析】

句意“所有的工厂不允许释放有害气体到空气中”。

allow doing sth“允许做某事”或allow sb to do sth“允许某人做某事”。变为被动为be allow to do sth“被允许做某事”，故选D。