.Is your sister a factory worker or a doctor?. A. Yes she isB. No she isn’tC. A

问题补充：

.--- Is your sister a factory worker or a doctor?

--- .

A. Yes, she is

B. No, she isn’t

C. A factory worker

D. Yes, she is a doctor

答案：

A. Yes, she is

B. No, she isn’t

(答案→)C. A factory worker

D. Yes, she is a doctor

解析：根据or可知，本句是一个选择疑问句，不能用yes或no回答，故应将ABD排除。所以本题选C。