3/4冠修复前牙时若切缘太薄可不作（）
A.邻面片切
B.切缘磨除
C.切沟制备
D.舌面磨除
E.唇面磨除
参考答案：C
The shop assistant said he knew . [ ]
A. where does the manager live
B. where the manager lives
C. where did the manager live
D. where the manager lived
基准试剂规定采用( )标签。
A．红色
B．浅绿色
C．绿色
D．蓝色
