选择合适的选项补全对话。
A．How much are they?
B．Can I help you?
C. OK. We'll take them
D. What size ?
E. Yes. But I like the blue pair．
A:____
B: Yes．A pair of shoes for my son．
A:____
B: Size6．
A: How about this pair?
B: Are they nice，John?
C:____
B: Are the blue ones all right?
C: Yes．they are．
B:____
A: They are 40 yuan．
B:____
