——Doctor what do you think about the operation on my mom?——Couldn’t be better．I’m sure sh

问题补充：

——Doctor, what do you think about the operation on my mom?

——Couldn’t be better．I’m sure she’ll recover .

A. one by one

B. side by side

C. by and by

D. by the by

答案：

A. one by one

B. side by side

(答案→)C. by and by

D. by the by

解析：by and by不久，马上； side by side肩并肩地； one by one逐个地，一个接一个地； by the by 顺便提一下.从句意来看，C项适合。