关于全口义齿平面位置测定下列哪一项是错误的()
A.与瞳孔连线平行
B.与鼻翼耳屏连线平行
C.与下颌两侧牙槽嵴平行
D.平分颌间距离
E.在上唇下缘以下2mm
参考答案:C
This machine is very easy ________. Anybody can learn to use it in a few minutes.[ ]
A. operating
B. to be operating
C. operated
D. to operate
注塑薄壁制品时哪种工艺条件相对比较理想()
A、快速
B、慢速
C、快速短射