Police dog trainer Guan Zihan ties a Chinese knot on the neck of his dog in Haikou, south China's Hainan Province, Feb. 9, 2018. Police dog trainers and their dog here celebrate the day of Xiaonian by being together. Xiaonian falls on the 23rd or 24th day of the last month of the Chinese traditional lunar calendar, marking the start of the countdown to Chinese Year of the Dog. (Xinhua/Jiang Bo)