Crew members pose for photos with a CR400AF Fuxing intelligent bullet train in southwest China's Chongqing, June 23, 2021. The CR400AF Fuxing intelligent bullet train will be put into service on the railway linking Chengdu, capital city of southwest China's Sichuang Province, and Chongqing on Friday. (Photos: Xinhua)

A crew member walks past a CR400AF Fuxing intelligent bullet train in southwest China's Chongqing, June 23, 2021. The CR400AF Fuxing intelligent bullet train will be put into service on the railway linking Chengdu, capital city of southwest China's Sichuang Province, and Chongqing on Friday.

A crew member shows the function of on-board equipment on a CR400AF Fuxing intelligent bullet train in southwest China's Chongqing, June 23, 2021. The CR400AF Fuxing intelligent bullet train will be put into service on the railway linking Chengdu, capital city of southwest China's Sichuang Province, and Chongqing on Friday.

A crew member shows the function of on-board equipment on a CR400AF Fuxing intelligent bullet train in southwest China's Chongqing, June 23, 2021. The CR400AF Fuxing intelligent bullet train will be put into service on the railway linking Chengdu, capital city of southwest China's Sichuang Province, and Chongqing on Friday.

A crew member shows the function of on-board equipment on a CR400AF Fuxing intelligent bullet train in southwest China's Chongqing, June 23, 2021. The CR400AF Fuxing intelligent bullet train will be put into service on the railway linking Chengdu, capital city of southwest China's Sichuang Province, and Chongqing on Friday.

Photo taken on June 23, 2021 shows a CR400AF Fuxing intelligent bullet train and the crew members in southwest China's Chongqing. The CR400AF Fuxing intelligent bullet train will be put into service on the railway linking Chengdu, capital city of southwest China's Sichuang Province, and Chongqing on Friday.

A crew member walks on a CR400AF Fuxing intelligent bullet train in southwest China's Chongqing, June 23, 2021. The CR400AF Fuxing intelligent bullet train will be put into service on the railway linking Chengdu, capital city of southwest China's Sichuang Province, and Chongqing on Friday.

A crew member walks on a CR400AF Fuxing intelligent bullet train in southwest China's Chongqing, June 23, 2021. The CR400AF Fuxing intelligent bullet train will be put into service on the railway linking Chengdu, capital city of southwest China's Sichuang Province, and Chongqing on Friday.

Crew members pose for photos with a CR400AF Fuxing intelligent bullet train in southwest China's Chongqing, June 23, 2021. The CR400AF Fuxing intelligent bullet train will be put into service on the railway linking Chengdu, capital city of southwest China's Sichuang Province, and Chongqing on Friday.