题干
听第四段对话，回答小题。
What does the man want to buy?
A：Shirt．
B：Trousers．
C：Skirt．
答案(点此获取答案解析）
A
What does the man want to buy?
A：Shirt．
B：Trousers．
C：Skirt．
①只有在市场上出现C点时，才是等价交换