Sir,
In reply to your advertisement in today's China Daily regarding a vacancy in your office, I wish to apply for the position of senior clerk, which you have specified.
 I feel sure that I can meet your special requirements that the candidate must have a high command of English, for I graduated from the English Language Department of Wuhan University three years ago.
In addition to my study of English in the university, I have worked for three years as a secretary in the firm of ABC Trading Co. Ltd.
The main reason for changing my employment is to gain more experience with a superior trading company like yours.I believe that my education and experience will prove useful for work in your office.
I am enclosing my resume, certificate of graduation and a letter of recommendation from the president of the university.I shall be obliged if you will give me a personal interview at your convenience.
Very truly yours,
                                                            Li Mei
The author thinks   _   is (are) his advantage(s) to get the employment.
his good command of English his working experience his certificate and the letter of recommendation both A and B