最常采用的固位体形式是（）

A.全冠

B.部分冠

C.嵌体

D.根内固位体

E.开面冠

I once thought Jonna was a good student, for she often got a high mark but ________ she was found

out to often cheat in examinations.[ ]

A. actually  

B. truly

C. surely  

D. mostly