A visitor looks at an unattended vending machine during the 2018 Shanghai International Unattended Retail Exhibition in east China's Shanghai, Aug. 15, 2018. The exhibition kicked off here on Wednesday, displaying unattended retail modes including vending machine, convenience store, restaurant, fuelling station, laundry and some other amusement and leisure services. (Xinhua/Fang Zhe)

Visitors look at an unattended vending machine during the 2018 Shanghai International Unattended Retail Exhibition in east China's Shanghai, Aug. 15, 2018. The exhibition kicked off here on Wednesday, displaying unattended retail modes including vending machine, convenience store, restaurant, fuelling station, laundry and some other amusement and leisure services. (Xinhua/Fang Zhe)

An exhibitor (L) introduces an intelligent settlement system to visitors during the 2018 Shanghai International Unattended Retail Exhibition in east China's Shanghai, Aug. 15, 2018. The exhibition kicked off here on Wednesday, displaying unattended retail modes including vending machine, convenience store, restaurant, fuelling station, laundry and some other amusement and leisure services. (Xinhua/Fang Zhe)

A visitor takes photos of an intelligent retail robot during the 2018 Shanghai International Unattended Retail Exhibition in east China's Shanghai, Aug. 15, 2018. The exhibition kicked off here on Wednesday, displaying unattended retail modes including vending machine, convenience store, restaurant, fuelling station, laundry and some other amusement and leisure services. (Xinhua/Fang Zhe)

People visit an unattended convenience store during the 2018 Shanghai International Unattended Retail Exhibition in east China's Shanghai, Aug. 15, 2018. The exhibition kicked off here on Wednesday, displaying unattended retail modes including vending machine, convenience store, restaurant, fuelling station, laundry and some other amusement and leisure services. (Xinhua/Fang Zhe)

A child enters a simulated unattended convenience store during the 2018 Shanghai International Unattended Retail Exhibition in east China's Shanghai, Aug. 15, 2018. The exhibition kicked off here on Wednesday, displaying unattended retail modes including vending machine, convenience store, restaurant, fuelling station, laundry and some other amusement and leisure services. (Xinhua/Fang Zhe)