问题补充:
His sister left home in , and__since.
A. had not been heard of
B. has not been heard of
C. had not heard of
D. has not heard of
答案:
A. had not been heard of
(答案→)B. has not been heard of
C. had not heard of
D. has not heard of
解析:考查时态语态,时间是副词since“自从那时”,用现在完成时,而且his sister和hear of是被动关系,所以选B,句意是:他姐姐离开家,自从那时一直没有音讯。