437.The moment the 28th Olympic Games _____ open,the whole world cheered.
A.declared
B.have been declared
C.have declared
D.were declared
438.My cousin went to Canada two years ago. He _____ there for a few months and then went to America.
A.worked
B.would work
C.would be working
D.has been working
437.答案是D;the 28th Olympic Games作主语,应用被动语态;根据下文cheered暗示，应用过去时。
438.答案是A;句中and连接两个发生在过去的动作，时态应该一致。
