dear sir，
i am writing to inquire whether you will have any vacancies for a senior clerk in the near future。 i have heard that you hire senior clerk from time to time and i hope you will consider my application。 please favour me with an interview if you think i might be acceptable。
i have been working in the library at shue yan college for two years。 i believe that my english is good enough for your needs。 my typing speed is about 75 words。 i am enclosing a resume for your reference。
sincerely yours，