售：Can I help you?
客：Oh,I want to buy some pen.
售：Ok,let me help you.Follow me.
客：How much is this pen?
售：This red pen is sixteen yuan.Are you want to buy this?
客：Oh,That's to expensive.How about this one?
售：This one is five yuan.
客：Oh,I buy five.
售：OK,It's twenty-five yuan.
Here you are.Bye~
客：Bye~