题目内容：

You can do what you want to do _____ your birthday.

优质解答

on your birthday 具体一天,用on.

追问：

Do you know that ______ at the door?He will have a personal talk only with me.(person) 能帮我回答一下这道题么？

追答：

Do you know that (person) at the door?He will have a personal talk only with me.