1. Department of Special Education , Faculty of Education, , 3663 N. Zhongshan Rd, Shanghai , P.R. China
2. East China Normal University , Faculty of Education, , 3663 N. Zhongshan Rd, Shanghai , P.R. China
3. Institute of Special Education, Faculty of Education, Beijing Normal University , N. 19, Xinjiekouwai St, Haidian District, Beijing P.R. China