—Now computers _____ in many ways.

—I agree with you. I think they are the most useful inventions in the world. [ ]

A. used

B. use

C. are used

D. were used

腭侧基托过长，不密合（）。

A.义齿弹跳

B.基牙敏感，咬合不适

C.义齿摘戴困难

D.支托折断，义齿下沉

E.发音不清