A woman works in the field in Yangzhou, east China's Jiangsu Province, July 7, 2018. Saturday marks Xiaoshu, or Lesser Heat, the 11th of the 24 solar terms in the Chinese lunar calendar which means the beginning of hot summer. (Photo: Xinhua)

A man works in the field at Caibanyu Village of Lishan Sub-district in Yiyuan County, east China's Shandong Province, July 7, 2018. Saturday marks Xiaoshu, or Lesser Heat, the 11th of the 24 solar terms in the Chinese lunar calendar which means the beginning of hot summer. (Xinhua/Zhao Dongshan)

Aerial photo taken on July 7, 2018 shows people fertilizing mulberry at Liuwangzhuang Village of Gaoqing County, east China's Shandong Province. Saturday marks Xiaoshu, or Lesser Heat, the 11th of the 24 solar terms in the Chinese lunar calendar which means the beginning of hot summer.(Photo: Xinhua)

A woman works in the field at Huangzhuang Village of Yong'an Town in Zaozhuang, east China's Shandong Province, July 7, 2018. Saturday marks Xiaoshu, or Lesser Heat, the 11th of the 24 solar terms in the Chinese lunar calendar which means the beginning of hot summer. (Photo: Xinhua)

A woman works in the field at Beidayan Village in Lishan Sub-district of Yiyuan County, east China's Shandong Province, July 7, 2018. Saturday marks Xiaoshu, or Lesser Heat, the 11th of the 24 solar terms in the Chinese lunar calendar which means the beginning of hot summer. (Photo: Xinhua)

A woman works in the field at Heiya Village of Shiqiao Town in Yiyuan County, east China's Shandong Province, July 7, 2018. Saturday marks Xiaoshu, or Lesser Heat, the 11th of the 24 solar terms in the Chinese lunar calendar which means the beginning of hot summer. (Photo: Xinhua)