A villager works in a greenhouse at Xisanli Village of Xisanli Township in Zunhua City, north China's Hebei Province, Feb. 11, 2019. (Xinhua/Liu Mancang)

　　Villagers work in a greenhouse at Xisanli Village of Xisanli Township in Zunhua City, north China's Hebei Province, Feb. 11, 2019. (Xinhua/Liu Mancang)

　　Aerial photo shows farmers work at Lianxi Vegetable Base in Daoxian County of Yongzhou City, central of China's Hunan Province, Feb. 11, 2019. (Xinhua/He Hongfu)