Dear Mr. Smith,
Ms. Maria of your company has told me that your depart. needs a manager assistant, and I want to apply for the position. I graduated from the University of Business and Economy last year. My major is Human Resource and some experience in business has prepared me for the work you are calling for.
I am really interested in learning business practice. I will try my best to be a diligent worker and a fast learner. If given a chance, I am sure I can prove my worth in your company.