---The window must have taken you quite a lot of time that day.
--- You are right. They for weeks.
A. haven’t been cleaned
B. hadn’t been cleaned
C. didn’t’ clean
D. haven’t cleaned
网友回答
A. haven’t been cleaned
(答案→)B. hadn’t been cleaned
C. didn’t’ clean
D. haven’t cleaned
解析：
这题考查时态语态，窗户是被擦干净，所以用被动式，只能在AB之间选，根据句意：--那天擦窗户一定花了你很多时间，--对，它们几个星期没擦了。因为那天擦过了，所以用过去完成时。选B。