钎杆的破坏形式很多,但是()是主要的破坏形式。
A.钎尾推顶
B.炸顶
C.钎杆折断
D.钎尾磨损
参考答案:C
This construction firm has a long history, complete facilities, fine technique and service.
A.believable
B.similar
C.popular
D.considerate
铸造金属全冠牙体预备提供的面间隙一般为()
A.0.5~1mm
B.1~1.5mm
C.1.5~2.0mm
D.2.0~2.5mm
E.2.5~3mm