Each of the students in Grade Nine       looking forward to      a good result in the senior middle school entrance exam. Just work hard, then your dream will come true.

A. is ,have         B. are, having         C. is, having

牙脱位后，可能发生的并发症是（）

A.牙髓坏死

B.牙髓腔变窄或消失

C.牙根外吸收

D.边缘性牙槽突吸收

E.以上均正确