First of all, I would like to express my sincere and special gratitude to Mrs Nguyen Thi Hoa, the supervisor, who have generously given us invaluable assistance and guidance during the preparing for this research paper. I also offer my sincere thanks to Ms. Tran Thi Ngoc Lien, the Dean of Foreign Language Faculty at Haiphong Private University for her previous supportive lectures that helped me in preparing my graduation paper