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