【正确答案】Dear Li Liang,
This June 30th I will graduate, so I will hold a party on Saturday evening in my house. It would be pleasant to have you here.
So interesting will this party be that you can't afford to miss it. For one thing, we can have a big meal, sing the popular songs and play games. For another, it also provides a good opportunity for you to meet many friends that you haven't seen for a long time.
What an important thing it is to get your participation! First, you are my best friends and bring home to me many things. Second, we haven't seen each other for quite a long time and I am eager to see you. The party would not be complete without you!
The party will begin at 7:30 p.m. Is it possible for us to see you at 7:00 on Saturday evening in my house? I do hope you can come.