_______, he could not persuade her to accept his idea that wealth is more important than health. [ ]

A. Might as he try                

B. Try as he might

C. As he might try              

D. He might as try  

下列哪一项不是髓腔预备的要求（）

A.按牙位正确开髓

B.洞壁与根管为直线通路

C.揭净髓室顶

D.尽量扩大根管口

E.磨除牙本质突起