Aerial photo taken on June 5, 2019 shows workers unloading salt at a storing port of Nanbao Salt Farm in Caofeidian District of Tangshan, north China's Hebei Province, June 5, 2019. Spring harvest at Nanbao Salt Farm is coming to an end, with spring salt production expected to exceed 1.4 million tons this year. (Xinhua/Yang Shiyao)