干槽症通常发生在拔牙术后（）。
A.术后1～2小时
B.拔牙当日
C.术后2～3天
D.术后7～14天
E.术后1～2个月
参考答案：C
It was not until near the end of the letter ______ she mentioned her own plan.
A．where
B．that
C．why
D．when
临产
