建筑结构构造上，伸缩缝两侧必须断开的有（）。
A.基础
B.墙体
C.圈梁
D.屋架
E.楼板
参考答案：B, C, E
If you had joined the chat room ten minutes ago, you _____ what we were talking about.
A．will know
B．are knowing
C．can know
D．would have known
