【正确答案】[参考范文]
Jan. 7th. 2012
Dear sir/madam,
We would like to invite you to an formal presentation of our new product on the Hi-tech Trade Fair in Shenzhen. The presentation will take place at No.3 gold street, at 9 a.m on Nov.72011. There will also be a reception at 8 a.m. in the morning. We hope you and your colleagues will be able to attend. Please remember to bring your ID card and your invitation letter. You need to show us the invitation letter to receive a vip card of the fair on the reception. Our company Lenovo is a leading producer of high-quality Hi-tech products. As you well know, recent technological advances have made increasingly affordable to the public. Our new models offer superb quality and sophistication with economy, and their new features will give them distinct advantages over similar products from other manufacturers. Your attendance and advice on the fair will be very valuable.
We look forward to seeing you on Monday.
Just call our office at 4008100000 and we will be glad to secure a place for you.
Sincerely yours,
Jack Cheng

【答案解析】[解析]
邀请函主要是日常生活中用来邀请亲朋好友和相关人士参开某一活动或会议的信件。一般包括首先邀请人自我介绍，开门见山表明写作目的；其次邀请的具体活动和缘由以及具体安排(时间、地点等)；最后，一般是要求和希望包括尽快回复等。