A:
B:
C:
D:
(Ⅰ)求证:A1C∥平面AB1D;
(Ⅱ)求二面角B﹣AB1﹣D的正切值;
(Ⅲ)求点C到平面AB1D的距离.
— Lily is about the competition.
— Yes, she is afraid that she won't win.
下列各句中没有语病的一句是( )。