— Is your mother still a teacher?— .A. Yes she wasB. She didn’t use toC. No but she used

问题补充：

— Is your mother still a teacher?

— .

A. Yes, she was

B. She didn’t use to

C. No, but she used to

D. No, but she used to be

答案：

A. Yes, she was

B. She didn’t use to

C. No, but she used to

(答案→)D. No, but she used to be

解析：选D。used to be表示“曾经是……”，与现在有对比之意。to后的be要保留。