Dear________,
There will a ________________(内容) at/in________________(地点) on___________(时间). We would be honored to have you there with us.
The occasion will start at ___________(具体时间). This will be followed by a _______(进一步的安排). At around______(时间)，____________________________(另一个安排)
I really hope you can make it. RSVp before ____________(通知你的最后期限)
Yours sincerely
Li Ming