AcknowledgementsAfter four years study in University, I have learned a lot with the help of my classmates and all teachers
Each time when I was depressed, someone would give his/her hand for me
So, I am always very obliged to those who guided me, helped me and encouraged me to move forward to my life
At first, I am very gratitude to those teachers who have taught me and guided
You are a significant point in my life and I’ll remember the interesting lessons you have taught us forever
I have gained both knowledge and the way of life from your teaching and I hope I will be a teacher like you
Next, I am really grateful to my tutor Zhang Li
I complete my thesis with his help
He gave me much useful advice, which was really important to me
And he tried to give me direct and detailed guidan