Question

---Is your father a teacher?
---Well, he _______

1. A.
   used to
2. B.
   was used to
3. C.
   used to be
4. D.
   is used to be

Answer 1

C
考查情景交际和used to的用法。“你爸爸是老师吗？”“嗯，以前是。”答语的言外之意是现在不是老师了。used to do sth.“过去常常做某事”；be used to do sth.“被用来做某事”；used to be中的be不能省略。故选C。