让教授写啊，不会你就是被委托的教授吧？！
不好意思刚看到你的留言，我现在没时间写，从网上给你搜了一篇：
修改一下，譬如说名字之类的~
At the request of Mr. Xizhen Chen, my former student in the Department of Computer Science, Beijing Univ. of Sciences, I am glad to write this letter furnishing my evaluation ofhis academic aptitude for your reference. Mr. Chen is interested in your graduate program in Computer Science.I came to know him in September 1987 when Mr. Chen enrolled in my class on FORTRAN IV Programming, a three semesters' course.In the class he was one of the most outstanding students. At the semester final he earned a high grade of 81, which should be "A" according to our grading system. I also found him good at other studies.After the class, he had personal talks with me several times. He indicated a great interest in computer hardware, In my opinion, Mr. Chen has a potential in Computer Science, which can be further developed.In view of his previous achievements in this College, I am firmly convinced that Mr. Chen will make a successful graduate student. Your favorable consideration of his admission will be highly appreciated.
网址：
http://www.diyifanwen.com/qiuzhijiuzhi/jianliziliao/tuijianxin/20070923145352905.html