Photo taken on May 28, 2019 shows a paper box that can be recycled for packaging displayed during the 2019 Global Smart Logistics Summit in Hangzhou, capital of east China's Zhejiang Province. The 2019 Global Smart Logistics Summit kicked off on Tuesday in Hangzhou. (Xinhua/Huang Zongzhi)

People visit the exhibition area of Cainiao smart warehouse during the 2019 Global Smart Logistics Summit in Hangzhou, capital of east China's Zhejiang Province, May 28, 2019. The 2019 Global Smart Logistics Summit kicked off on Tuesday in Hangzhou. (Xinhua/Huang Zongzhi)

People visit the exhibition area of Cainiao smart warehouse during the 2019 Global Smart Logistics Summit in Hangzhou, capital of east China's Zhejiang Province, May 28, 2019. The 2019 Global Smart Logistics Summit kicked off on Tuesday in Hangzhou. (Xinhua/Huang Zongzhi)

People visit the exhibition area of Cainiao smart warehouse during the 2019 Global Smart Logistics Summit in Hangzhou, capital of east China's Zhejiang Province, May 28, 2019. The 2019 Global Smart Logistics Summit kicked off on Tuesday in Hangzhou. (Xinhua/Huang Zongzhi)

People visit the exhibition area of Cainiao smart warehouse during the 2019 Global Smart Logistics Summit in Hangzhou, capital of east China's Zhejiang Province, May 28, 2019. The 2019 Global Smart Logistics Summit kicked off on Tuesday in Hangzhou. (Xinhua/Huang Zongzhi)

A visitor takes pictures of an express delivery vehicle displayed at the exhibition area of China Post during the 2019 Global Smart Logistics Summit in Hangzhou, capital of east China's Zhejiang Province, May 28, 2019. The 2019 Global Smart Logistics Summit kicked off on Tuesday in Hangzhou. (Xinhua/Huang Zongzhi)