问题补充:
The house is dirty because itsince they moved out.
A. doesn’t clean
B. isn’t cleaned
C. hasn’t cleaned
D. hasn’t been cleaned
答案:
A. doesn’t clean
B. isn’t cleaned
C. hasn’t cleaned
(答案→)D. hasn’t been cleaned
解析:考查时态:句意:房子很脏,因为自从他们搬出去了一直没有被打扫。时间状语是since连接的时间状语从句,和现在完成时连用,因为the house和clean是被动关系,用现在完成时的被动。选D。