✔ 最佳答案
[Date]
[Address]
Dear [Ms. xxx],
Re: Invitation to [xxx] (name of event)
I am very delighted to accept your invitation to join [event name] at [location] on [date] at [time]. I look forward to seeing you on such special day that marks a new era of your company.
Yours sincerely,
[name]
Some website for reference:
http://www.writeexpress.com/old/accept09.html