【正确答案】 A Letter of Declination
Jan. 19th, 2013
Dear Mr. Smith,
Thank you for your letter of December 25, inviting me to give a speech on February 27 at the anniversary of Cambridge University. Apparently you have not heard that about two weeks ago I suffered from acute pneumonia and had to stay in the hospital for a number of days. Although I feel much better now, the doctor has advised me to take complete rest for at least one month.
In view of this, I regret that I am unable to accept your kind invitation to give the speech. I would like, however, to send my best wishes and congratulations to you on your anniversary.
Sincerely,
Li Ming
(111 words)

【答案解析】作者在第一段中所给出的拒绝理由具体真切，这是拒绝邀请信中所不可缺少的要素。