问题
选择题
---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
答案
答案：B
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。