Dear professor,

　　I am writing on behalf of the School of Foreign Language of Peking University to invite you to be a judge for the English speech contest to be held in our university。

　　We know that you have lots of experience and do have an eye for the brilliant performance in English speech contests. We would be appreciated if you could spare your time on Friday, May 10. The contest will be held in the auditorium from 3 p.m. to 6 p.m. Judges to be invited include another two professors who are very familiar to you。

　　We hope that you will accept our invitation if it is convenient for you. Please contact us at 1234567 if you have any question。

　　I am looking forward to your reply。

　　Yours sincerely,

　　Li Ming