问题补充:
Every possible means , but the teacher as well as the students found a solution to the problem yet.
A. has been tried; hasn’t
B. has tried; haven’t
C. have tried; haven’t
D. have been tried; hasn’t
答案:
(答案→)A. has been tried; hasn’t
B. has tried; haven’t
C. have tried; haven’t
D. have been tried; hasn’t
解析:考查主谓一致。means单复同形,与every修饰,谓语动词用单数;as well as连接两个主语,谓语动词与前一个主语保持一致,故选A。