Students from Chang'an University demonstrate a virtual reality (VR) security education system during the 2018 Shaanxi Higher Education Expo at the Qujiang International Conference and Exhibition Center in Xi'an, northwest China's Shaanxi Province, June 24, 2018. The four-day expo kicked off here on Sunday with the participation of 690 exhibitors which include higher education institutions, education service providers and related enterprises. (Xinhua/Liu Xiao)