Many thanks to my Chinese teachers  :

Wang Xindan, Kunming Normal University    Zhang Ling, Nanjing Normal University

Yuan Mei, Yang Yan, Li Ying, Qufu Normal University  

Pan Guini, Dai Yinfeng, Guo Yu, Liu Yunjing, Tao Shanshan, Fang Xiaobei, Shanghai Donghua University

Zhang Yan, Xi'an Jiaotong University