Zhang Deqing introduces health knowledges to villagers in Liyanjian Village, Yuandongtou Town, Yishui County, east China's Shandong Province, Aug. 16, 2018. Zhang has been the doctor of Yuandongtou Village of Yuandongtou Town in Shandong for more than 20 years. His work covers almost 2,000 villagers in three villages of Yuandongtou Town. As many households are scattered over the villages, Zhang has to climb rough mountain roads to visit patients. There are four generations of doctors now in Zhang's family, including Zhang's grandfather Zhang Daoli and father Zhang Zaiji. Zhang's two children graduated from medical colleges in 2017, to become the fourth Dr. Zhang in the town. (Xinhua/Guo Xulei)?