After three years of study, I am about to graduate. Both my studies and my life have gained a lot. I would like to thank all the teachers for their teaching. First of all, I would like to thank my mentor, Mr. Cui Bo, who has taught us many times on the topic selection and writing of our thesis. I would also like to thank all the teachers in the learning process, they have opened me a broader vision, let me learn how to realize my dreams; thank my friends for helping me to control myself in life; also thank me My parents, it is their support that made my study to a higher level. I want to say that you will always be my beacon, let me keep moving forward to my dreams!