Staff members adjust an LED display board at the National Exhibition and Convention Center (Shanghai), the venue of the second China International Import Expo (CIIE), in Shanghai, east China, Oct. 30, 2019. (Xinhua/Fang Zhe)

Volunteers for the upcoming second China International Import Expo (CIIE) get familiar with the venue at the National Exhibition and Convention Center (Shanghai) in Shanghai, east China, Oct. 30, 2019. (Xinhua/Fang Zhe)

Technicians work at the National Exhibition and Convention Center (Shanghai), the venue of the second China International Import Expo (CIIE), in Shanghai, east China, Oct. 30, 2019. (Xinhua/Fang Zhe)

A line of mascots Jinbao" of China International Import Expo (CIIE) are placed at the National Exhibition and Convention Center (Shanghai), the venue of the second China International Import Expo, in Shanghai, east China, Oct. 30, 2019. (Xinhua/Fang Zhe)

A staff member works at the National Exhibition and Convention Center (Shanghai), the venue of the second China International Import Expo (CIIE), in Shanghai, east China, Oct. 30, 2019. (Xinhua/Fang Zhe)

Staff members work at the National Exhibition and Convention Center (Shanghai), the venue of the second China International Import Expo (CIIE), in Shanghai, east China, Oct. 30, 2019. (Xinhua/Fang Zhe)

Staff members work at the National Exhibition and Convention Center (Shanghai), the venue of the second China International Import Expo (CIIE), in Shanghai, east China, Oct. 30, 2019. (Xinhua/Fang Zhe)

Staff members adjust a helicopter that is to be exhibited at the National Exhibition and Convention Center (Shanghai), the venue of the second China International Import Expo (CIIE), in Shanghai, east China, Oct. 30, 2019. (Xinhua/Fang Zhe)