成人正畸的施力原则是()
A.矫形力
B.较大的矫治力
C.柔和间断的矫治力
D.连续的矫治力
E.以上都不是
参考答案:C
I can't understand ___________her like that.
A. you treat
B. you to treat
C. why treat
D. you treating
螺距是指同一条螺旋线上的相邻两牙在中径线上对应两点间的轴向距离。( )