Farmers work at a carrot field in Zhangjiakou, north China's Hebei Province, May 14, 2018. (Xinhua/Yang Shiyao)

Farmers work at a carrot field in Zhangjiakou, north China's Hebei Province, May 14, 2018. (Xinhua/Yang Shiyao)

Farmers work at a carrot field in Zhangjiakou, north China's Hebei Province, May 14, 2018. (Xinhua/Yang Shiyao)