Visitors experience a flying simulator during the 14th China Xi'an International Science & Technology Industry Expo and Hard & Core Technology Industry Expo at Qujiang International Conference and Exhibition Center in Xi'an, capital city of northwest China's Shaanxi Province, Aug. 15, 2019. The expo opens on Thursday and will showcase fruits covering fields including artificial intelligence, aerospace, biological technology and information technology. (Xinhua/Liu Xiao)

An exhibitor introduces a model of an aeroplane to a visitor during the 14th China Xi'an International Science & Technology Industry Expo and Hard & Core Technology Industry Expo at Qujiang International Conference and Exhibition Center in Xi'an, capital city of northwest China's Shaanxi Province, Aug. 15, 2019. The expo opens on Thursday and will showcase fruits covering fields including artificial intelligence, aerospace, biological technology and information technology. (Xinhua/Liu Xiao)

A visitor views bullet train models during the 14th China Xi'an International Science & Technology Industry Expo and Hard & Core Technology Industry Expo at Qujiang International Conference and Exhibition Center in Xi'an, capital city of northwest China's Shaanxi Province, Aug. 15, 2019. The expo opens on Thursday and will showcase fruits covering fields including artificial intelligence, aerospace, biological technology and information technology. (Xinhua/Liu Xiao)

A child interacts with an android during the 14th China Xi'an International Science & Technology Industry Expo and Hard & Core Technology Industry Expo at Qujiang International Conference and Exhibition Center in Xi'an, capital city of northwest China's Shaanxi Province, Aug. 15, 2019. The expo opens on Thursday and will showcase fruits covering fields including artificial intelligence, aerospace, biological technology and information technology. (Xinhua/Liu Xiao)