Buyer(买家）.Saler(卖家）
S：what can I do for you
B:I want to buy something according to the list of shopping which my mother gives me .Here you are
S:Thanks ,I have a look it .Mum..All the items we have and I'm going to collect them for you .By the way ,you need 1 kilo of chicken legs ,2 kilos of tomatoes and 2 big bottles of coke ,sure?
B:course.
S:All the articles I have prepared for you ,here you are ,kid.
B:thanks !giving you cash ,please check it .
S:It's right ,welcome to next time ,goodbye
B:Bye!