时光飞逝，转眼间四年紧张而又充实的大学生生活即将画上句号。在这四年的学

Time flies, blink of an eye four years of intense and fulfilling student life is about ends. During the four years of study, I got a lot of teachers, students and friends of the care and help. In the dissertation is nearing completion on the occasion, I would like to give all my support period, help and encourage people to express my most sincere thanks.

Time flies, the four years of intense and full college life is coming to an end. During this four years of study, I have received a lot of teachers, classmates and friends care and help. As my thesis is nearing completion, I would like to express my most sincere thanks to all those who have given me my support, help and encouragement during my stay.

Time flies, and in an instant, four years of intense and fulfilling college life will come to an end. During these four years of study, I have received a lot of care and help from teachers, classmates and friends. I would like to express my most sincere thanks to those who have supported me, helped me and encouraged me during the whole period of my dissertation.