问题补充：
--- What’s your brother?
---He a teacher, but now he is a doctor.
A. used to be
B. was used to
C. use to be
D. is used to be
答案：
(答案→)A. used to be
B. was used to
C. use to be
D. is used to be
解析：考察used用法。Be used to sth习惯于某事，used to do sth过去常常做某事。句意：你哥哥做什么工作？本句根据后文but now he is a doctor.，可知前文说的是过去常常做某事，故选A
