问题补充：
---?
---She is a shop assistant in the biggest mall.
A. How old is your sister
B. What’s the matter with your sister
C. Where does your sister work
D. What does your sister do?
答案：
A. How old is your sister
B. What’s the matter with your sister
C. Where does your sister work
(答案→)D. What does your sister do?
解析：
这题是根据答语选择问题，答语是：她是个最大的商城的营业员。所以问题是问她的职业，故选D，意思是：你姐姐是做什么的？
