acknowledgement：first I appreciate my country who give me a comfortable learning atmosphere，second i want to thanks my supervisor(指导老师）for his help and XXXX during the my I want to let them know that:you are my proud of my being with your guys is the happiest time I ever had。also I have a word to my gf:thanks for shareing with me all the crying or laughing you are so sweet，oh，god，I couldnot help crying at this moment
