A traffic signal for camels begins operation at the scenic spot of Mingsha Mountain and Crescent Spring in Dunhuang City, northwest China's Gansu Province, April 11, 2021. [Photo/China News Service]

A traffic signal for camels begins operation at the scenic spot of Mingsha Mountain and Crescent Spring in Dunhuang City, northwest China's Gansu Province, April 11, 2021. [Photo/China News Service]

Tourists take photos of the traffic signal for camels at the scenic spot of Mingsha Mountain and Crescent Spring in Dunhuang City, northwest China's Gansu Province, April 11, 2021. [Photo/China News Service]

Camels pass the road when the green traffic signal is on at the scenic spot of Mingsha Mountain and Crescent Spring in Dunhuang City, Northwest China's Gansu Province, April 11, 2021. [Photo/China News Service]

Camels pass the road when the green traffic signal is on at the scenic spot of Mingsha Mountain and Crescent Spring in Dunhuang City, Northwest China's Gansu Province, April 11, 2021. [Photo/China News Service]

Tourists pass the road when the red traffic signal for camels is on at the scenic spot of Mingsha Mountain and Crescent Spring in Dunhuang City, Northwest China's Gansu Province, April 11, 2021. [Photo/China News Service]