Photo taken on May 16, 2019 shows two golden monkeys at Dalongtan Golden Monkey Research Center in Shennongjia National Park of central China's Hubei Province. With the efforts of local authority and improvement of the environment, the number of golden monkeys in Shennongjia area has doubled compared to that in the 1980s. (Xinhua/Liu Lianfen)

Photo taken on May 16, 2019 shows golden monkeys at Dalongtan Golden Monkey Research Center in Shennongjia National Park of central China's Hubei Province. With the efforts of local authority and improvement of the environment, the number of golden monkeys in Shennongjia area has doubled compared to that in the 1980s. (Xinhua/Liu Lianfen)

Photo taken on May 16, 2019 shows golden monkeys at Dalongtan Golden Monkey Research Center in Shennongjia National Park of central China's Hubei Province. With the efforts of local authority and improvement of the environment, the number of golden monkeys in Shennongjia area has doubled compared to that in the 1980s. (Xinhua/Liu Lianfen)

Photo taken on May 16, 2019 shows two golden monkeys at Dalongtan Golden Monkey Research Center in Shennongjia National Park of central China's Hubei Province. With the efforts of local authority and improvement of the environment, the number of golden monkeys in Shennongjia area has doubled compared to that in the 1980s. (Xinhua/Liu Lianfen)

Photo taken on May 16, 2019 shows golden monkeys at Dalongtan Golden Monkey Research Center in Shennongjia National Park of central China's Hubei Province. With the efforts of local authority and improvement of the environment, the number of golden monkeys in Shennongjia area has doubled compared to that in the 1980s. (Xinhua/Liu Lianfen)

Photo taken on May 16, 2019 shows golden monkeys at Dalongtan Golden Monkey Research Center in Shennongjia National Park of central China's Hubei Province. With the efforts of local authority and improvement of the environment, the number of golden monkeys in Shennongjia area has doubled compared to that in the 1980s. (Xinhua/Dong Jianghui)

Photo taken on May 16, 2019 shows golden monkeys at Dalongtan Golden Monkey Research Center in Shennongjia National Park of central China's Hubei Province. With the efforts of local authority and improvement of the environment, the number of golden monkeys in Shennongjia area has doubled compared to that in the 1980s. (Xinhua/Liu Lianfen)