[Luan, Lin; Dong, Yan] Beijing Normal Univ, Fac Educ, Sch Educ Technol, Beijing 100875, Peoples R China.
[Luan, Lin] Beijing Univ Posts & Telecommun, Dept Foreign Languages, Beijing, Peoples R China.
[Hong, Jon-Chao] Natl Taiwan Normal Univ, Taipei, Taiwan.
[Cao, Miao] Shandong Normal Univ, Jinan, Peoples R China.
[Hou, Xiaoju] Cent China Normal Univ, Natl Engn Res Ctr E Learning, Wuhan, Peoples R China.