-Mrs. Smith never thought his son could make such great progress, ______?

-______, because he had never got such good scores before.[ ]

A. could she; Yes, he could

B. did she; Yes, she did

C. couldn't she; No, he couldn't

D. did she; No, she didn't

窗框外面与墙面固定，为了在墙面抹灰时，将砂浆压入，使接缝严密，常在窗框外侧做槽。( )