下颌第一前磨牙牙合面似（）。
A.方圆形
B.卵圆形
C.扁圆形
D.四边形
E.圆三角形
参考答案：B
He is no longer in good condition, and his ability to work is limited. I ____________ him to give up the job but failed.
A．suggested
B．persuaded
C．tried to persuade
D．managed
目前公认的楔状缺损致病因素如下，除外
A．酸蚀
B．横刷牙
C．应力疲劳
D．牙龈退缩
E．牙颈部结构薄弱
