Visitors view the exhibits during the bauma CHINA 2020, the International Trade Fair for Construction Machinery, Building Material Machines, Mining Machines and Construction Vehicles, in east China's Shanghai, Nov. 24, 2020. The exhibition kicked off here on Tuesday. (Xinhua/Fang Zhe)

Visitors view the exhibits during the bauma CHINA 2020, the International Trade Fair for Construction Machinery, Building Material Machines, Mining Machines and Construction Vehicles, in east China's Shanghai, Nov. 24, 2020. The exhibition kicked off here on Tuesday. (Xinhua/Fang Zhe)

Visitors view the exhibits during the bauma CHINA 2020, the International Trade Fair for Construction Machinery, Building Material Machines, Mining Machines and Construction Vehicles, in east China's Shanghai, Nov. 24, 2020. The exhibition kicked off here on Tuesday. (Xinhua/Fang Zhe)

Visitors view the exhibits during the bauma CHINA 2020, the International Trade Fair for Construction Machinery, Building Material Machines, Mining Machines and Construction Vehicles, in east China's Shanghai, Nov. 24, 2020. The exhibition kicked off here on Tuesday. (Xinhua/Fang Zhe)

Visitors view the exhibits during the bauma CHINA 2020, the International Trade Fair for Construction Machinery, Building Material Machines, Mining Machines and Construction Vehicles, in east China's Shanghai, Nov. 24, 2020. The exhibition kicked off here on Tuesday. (Xinhua/Fang Zhe)