Wang Zheng nurses a chimpanzee cub at Beijing Zoo in Beijing, capital of China, July 14, 2022. Wang Zheng has worked at the Gorilla House of Beijing Zoo for 17 years. He takes care of all aspects about the animals living here. As a breeder, Wang needs to learn and understand the animals' psychological activities, temper, and their behavioral patterns for better breeding.Photo: Xinhua

Wang Zheng nurses a chimpanzee cub at Beijing Zoo in Beijing, capital of China, July 14, 2022. Wang Zheng has worked at the Gorilla House of Beijing Zoo for 17 years. He takes care of all aspects about the animals living here. As a breeder, Wang needs to learn and understand the animals' psychological activities, temper, and their behavioral patterns for better breeding.Photo: Xinhua

Chimpanzees eat fruits at Beijing Zoo in Beijing, capital of China, July 14, 2022. Wang Zheng has worked at the Gorilla House of Beijing Zoo for 17 years.Photo: Xinhua

Wang Zheng trims nails for Nan Nan at Beijing Zoo in Beijing, capital of China, July 14, 2022. Wang Zheng has worked at the Gorilla House of Beijing Zoo for 17 years. Photo: Xinhua

Wang Zheng offers watermelon to a chimpanzee at Beijing Zoo in Beijing, capital of China, July 14, 2022. Photo: Xinhua

Wang Zheng offers ice to a chimpanzee at Beijing Zoo in Beijing, capital of China, July 14, 2022. Photo: Xinhua

Nan Nan plays with her cub at Beijing Zoo in Beijing, capital of China, July 14, 2022. Photo: Xinhua

Wang Zheng prepares breakfast for chimpanzees at Beijing Zoo in Beijing, capital of China, July 14, 2022. Photo: Xinhua