A police officer in Bangjinmeiduo passport application room explains the details of applying for a border passport in Lhasa, capital of southwest China's Tibet Autonomous Region on July 21, 2017. The Bangjinmeiduo passport application room was open for the public to visit on Friday, which has attacted many pupils of Lhasa to learn relative knowledge and strengthen the consciousness of national defense. (Xinhua/Liu Dongjun)

A police officer in Bangjinmeiduo passport application room explains the details of applying for a border passport in Lhasa, capital of southwest China's Tibet Autonomous Region on July 21, 2017. The Bangjinmeiduo passport application room was open for the public to visit on Friday, which has attacted many pupils of Lhasa to learn relative knowledge and strengthen the consciousness of national defense. (Xinhua/Liu Dongjun)

A police officer in Bangjinmeiduo passport application room explains the meaning of different seals on a border passport in Lhasa, capital of southwest China's Tibet Autonomous Region on July 21, 2017. The Bangjinmeiduo passport application room was open for the public to visit on Friday, which has attacted many pupils of Lhasa to learn relative knowledge and strengthen the consciousness of national defense. (Xinhua/Liu Dongjun)

Editor: Liangyu