Police dog Wang Zi interacts with its trainer Song Wenlong at Chengdu East Railway station, in Chengdu, capital of southwest China's Sichuan Province, Feb. 1, 2018. The 8-year-old male labrador, named Wang Zi or prince in English, patrols the Chengdu East Railway station for the sake of passenger safety on the first day of Chunyun, or the Spring Festival travel rush. (Xinhua/Xue Yubin)