Clerk:Can I help you?Mary:Yes,please.I want socks.Clerk:What color do you want?Mary:Green.

Clerk:Can I help you?Mary:Yes,please.I want socks.Clerk:What color do you want?Mary:Green.
Clerk:Here you are.
Mary:How much are it?
Clerk:Four dollars.
Mary:I'll take it.Thanks.
Clerk:You're welcome.
(第6句和第8句哪里错了,怎么改,