免疫球蛋白的型的分类是根据（） A.CH氨基酸的组成和排列顺序的差异及其抗原特异性的

（Mrs. Green wants to buy a pair of shoes for her daughter.）
A:  1 
B: Yes, please. I want to buy a pair of shoes for my daughter.
A: These shoes are for girls. They are in all colors.   2 

A. How much are they? B. Can I help you? C. Yes, I do. D. What color does she like? E. What do you think of the shoes?

B: She likes red.
A: Look! What about these ones?
B: All right. Let me have a look.
…
B:   3  
A: They are very nice, but they are a little small.
Do you have big ones?
B:   4   Here you are!
A:   5  
B: 60 yuan.
A: They are fine. I’ll take it.
1.           2.           3.           4.           5.