Dear Mr. Brown,Thank you for your letter of 6 September regarding Mr. John Green who has been employed by this company for the past 10 years.Mr. Green served his apprenticeship (学徒) with Vickers Tools Ltd. in Manchester, followed by a three-year course of engineering for Production Engineers. He is technically well-qualified and for the past five years has been our Assistant Works Manager responsible for production and related business in our Sheffield factory. In all his job duties he has shown himself to be hard-working, responsible and in every way a very dependable employee.I can strongly recommend Mr. Green as I feel sure that if he were to be chosen to manage your factory in Nairobi he would bring to his work a true atmosphere of teamwork, which would be found necessary and helpful by all who would work with him.Sincerely yours,Tom Smith What job position has Mr. Green held in the past five years？（）