— You should apologize to her, Barry.

—______, but it’s not going to be easy.

A．I suppose so

B．I feel so

C．I do so

D．I like to

提供产生牙齿矫治力的基础是（）。

A.基牙

B.牙槽骨

C.口腔黏膜

D.支抗

E.矫治力