下列哪种因素可引起水平型食物嵌塞()
A.牙合面磨损
B.充填式牙尖
C.修复体未能完善地恢复接触
D.龈 * * 退缩,龈外展隙增大
E.接触点异常
参考答案:D
How beautiful she sings! I have never heard __.
A.the better voice
B.a good voice
C.the best voice
D.a better voice