以下预后最佳的牙齿折断是（）
A.冠折露髓
B.牙根近冠1／3根折
C.牙根中1／3根折
D.牙根尖1／3折断
E.冠根联合折断露髓
参考答案：D
Speaker A. Can you come to my office early to help me with my paperSpeaker B: ______
A．Thank you for your invitation. I'm sure to be there.
B．I'd like to, but I can't leave until I've typed out the letters.
C．By all means. I have to finish my own paper first.
D．What do you expect me to do for you
毛周角化症与下列哪项相关（）
A.编码K5和K14的基因突变
B.编码板层素5和ⅩⅦ型胶原基因突变
C.编码Ⅶ型胶原基因突变
D.角化细胞黏附障碍
E.类固醇硫酸酯基因缺陷
