at the party还是in the party?

记住以下表达
at the party // at the birthday party
in the course of the (birthday) party

其实,at the party 或 on the party都可以,具体怎么用,要看语境.基本上没有in the party（除非party是政党的意思,但题目已经指明是派对）
举例：
Here is a rough guide to show you how many varieties of food and drink you will need at the party,
这里有个指南,告诉你如何为派对准备多种食品和饮料.
On the party,the host announced their engagement.
在派对上,主持人宣布了他们订婚的消息.
John and Mary first met each other on a friend’s birthday party.
约翰和玛丽最初在朋友的生日派对上认识.
或者大致上这么说吧,谈论到人,用on the party,谈论到事情,at the party.On the party其实用得颇多,但具体使用时仍须看语境和具体要说什么.