国产精品永久免费视频- 无码精品A∨在线观看中文 -热re99久久精品国产99热-国产成人久久777777

Delegates watch an exhibition during the 25th International Council for Open and Distance Education (ICDE) World Conference, in north China's Tianjin, Oct 16, 2013. Delegates of 313 universities from home and abroad participated in the three-day conference, which opened in Tianjin on Wednesday. (Xinhua/Li Xiang)

Delegates watch an exhibition during the 25th International Council for Open and Distance Education (ICDE) World Conference, in north China's Tianjin, Oct 16, 2013. Delegates of 313 universities from home and abroad participated in the three-day conference, which opened in Tianjin on Wednesday. (Xinhua/Li Xiang)