A man tries a ticket checking machine at China International Rail Transit and Equipment Manufacturing Industry Exposition in Zhuzhou, central China's Hunan Province, Dec. 8, 2021. The expo kicked off here on Wednesday. (Xinhua/Chen Sihan)

A woman tries a VR device at China International Rail Transit and Equipment Manufacturing Industry Exposition in Zhuzhou, central China's Hunan Province, Dec. 8, 2021. The expo kicked off here on Wednesday. (Xinhua/Chen Sihan)

A woman views the exhibits at China International Rail Transit and Equipment Manufacturing Industry Exposition in Zhuzhou, central China's Hunan Province, Dec. 8, 2021. The expo kicked off here on Wednesday. (Xinhua/Chen Sihan)

A man tries a VR device at China International Rail Transit and Equipment Manufacturing Industry Exposition in Zhuzhou, central China's Hunan Province, Dec. 8, 2021. The expo kicked off here on Wednesday. (Xinhua/Chen Sihan)

Photo taken on Dec. 8, 2021 shows the venue of China International Rail Transit and Equipment Manufacturing Industry Exposition in Zhuzhou, central China's Hunan Province. The expo kicked off here on Wednesday. (Xinhua/Chen Sihan)

People view the exhibits at China International Rail Transit and Equipment Manufacturing Industry Exposition in Zhuzhou, central China's Hunan Province, Dec. 8, 2021. The expo kicked off here on Wednesday. (Xinhua/Chen Sihan)

Aerial photo taken on Dec. 8, 2021 shows people viewing the exhibits at China International Rail Transit and Equipment Manufacturing Industry Exposition in Zhuzhou, central China's Hunan Province. The expo kicked off here on Wednesday. (Xinhua/Chen Sihan)

A staff member presents a rail transit product via an AR device at China International Rail Transit and Equipment Manufacturing Industry Exposition in Zhuzhou, central China's Hunan Province, Dec. 8, 2021. The expo kicked off here on Wednesday. (Xinhua/Chen Sihan)

People view the exhibits at China International Rail Transit and Equipment Manufacturing Industry Exposition in Zhuzhou, central China's Hunan Province, Dec. 8, 2021. The expo kicked off here on Wednesday. (Xinhua/Chen Sihan)