— I left my handbag  on the train, but luckily someone gave it  to a railway official.  

— How unbelievable to get it back! I mean, someone _____ it.     [ ]

A. will have stolen    

B. might have stolen      

C. should have stolen      

D. must have stolen

有关后牙3/4冠的牙体预备正确的是（）。

A．正常关系时，冠的边缘要覆盖颊、舌尖

B．舌面预备可不去除倒凹

C．邻面轴沟可预备在邻面舌侧1/3与中1/3交界处

D．面沟预备是为了防止修复体向脱位

E．必要时可在邻面增加邻面轴沟数目，或在面增加钉洞固位形