This graduation paper is the result of my continuous working time. I would
like to take this opportunity to express my particular thanks to my supervisor,
Ms Nguyen Thi Thu Huyen, BA of Hai Phong Private University, for her
enormously helpful and effective instructions, constant and tireless help and
support throughout the study.
I would like to show my deepest gratitude to all l ectures in English
Department of Hai Phong Private University.
I also would like to give my thanks to all pre -researchers and authors for
their beneficial materials used in this graduation paper