This afternoon our laboratory held the last discussion lecture of this semester. The same as one year ago, it is time for the fellow students to leave. Chunan Chen, Kunjie Chen and Peng Liu are three masters who graduate this year. I remember when Iwas in my sophormore year taking the data structure course, they three are the specific TAs of the course. It was then when I met my mentor today and changed my college life. Time flies, during the three semesters in the laboratory, we have experienced so many anecdotes. We do research together, discuss all kinds of things happened in the outside world, present our work and report papers. They have helped me so much with all kinds of daily affairs, they encouraged me when I was in the darkness, they point me the road when I was confused. Because of them, I changed my route from pure developing towards researching. Because of them, I decided to obtain a better education abroad. Because of them, my life have changed so much towards a more brilliant direction. I appreciate them so much. However, it is time to say goodbye.From now on we cannot meet frequently any more. Every one has his only life routine, and the only words I can say to them are, good luck for everything and wish you ahappy life.