一Is your sister a worker or a doctor?— A. She is twenty．B. No she isn’tC. She is a doctor

问题补充：

一Is your sister a worker or a doctor?

— ．

A. She is twenty．

B. No，she isn’t

C. She is a doctor

D. She likes her job

答案：

A. She is twenty．

B. No，she isn’t

(答案→)C. She is a doctor

D. She likes her job

解析：本题是一个选择疑问句，要么回答她是一名工人，要么回答她是一名医生，故本题选C。