A farmer works in a field in Fanjiatai Village of Difang Town, Pingyi County, Linyi City, east China's Shandong Province, April 18, 2020. The upcoming Guyu, literally meaning "Rain of Millet", is the sixth of the 24 solar terms created by ancient Chinese to carry out agricultural activities. For the year 2020, the day of Guyu falls on April 19. (Photo by Wu Jiquan/Xinhua)

Farmers work in a field in Luancheng District of Shijiangzhuang, north China's Hebei Province, in this aerial photo taken on April 18, 2020. The upcoming Guyu, literally meaning "Rain of Millet", is the sixth of the 24 solar terms created by ancient Chinese to carry out agricultural activities. For the year 2020, the day of Guyu falls on April 19. (Photo by Li Mingfa/Xinhua)

A farmer works in an orchard in Wanggezhuang Village of Wangtan Town, Tangshan City, north China's Heibei Province, April 18, 2020. The upcoming Guyu, literally meaning "Rain of Millet", is the sixth of the 24 solar terms created by ancient Chinese to carry out agricultural activities. For the year 2020, the day of Guyu falls on April 19. (Photo by Li Lei/Xinhua)

Farmers work in a field in Lucun Town, Qiyuan County, Zibo City, east China's Shandong Province, April 18, 2020. The upcoming Guyu, literally meaning "Rain of Millet", is the sixth of the 24 solar terms created by ancient Chinese to carry out agricultural activities. For the year 2020, the day of Guyu falls on April 19. (Photo by Zhao Dongshan/Xinhua)

Farmers work in a field in Xiaji Town of Baoying County, in Yangzhou, east China's Jiangsu Province, in this aerial photo taken on April 18, 2020. The upcoming Guyu, literally meaning "Rain of Millet", is the sixth of the 24 solar terms created by ancient Chinese to carry out agricultural activities. For the year 2020, the day of Guyu falls on April 19. (Photo by Shen Dongbing/Xinhua)

A farmer works in a field in Bandahu Village of Shadaogou Town, Xuan'en County, central China's Hubei Province, April 18, 2020. The upcoming Guyu, literally meaning "Rain of Millet", is the sixth of the 24 solar terms created by ancient Chinese to carry out agricultural activities. For the year 2020, the day of Guyu falls on April 19. (Photo by Wang Jun/Xinhua)

A farmer works in a field in Lucun Town, Qiyuan County, Zibo City, east China's Shandong Province, April 18, 2020. The upcoming Guyu, literally meaning "Rain of Millet", is the sixth of the 24 solar terms created by ancient Chinese to carry out agricultural activities. For the year 2020, the day of Guyu falls on April 19. (Photo by Zhao Dongshan/Xinhua)

Staff members operate drones in a field in a cooperative of Qingzhou City, east China's Shandong Province, April 18, 2020. The upcoming Guyu, literally meaning "Rain of Millet", is the sixth of the 24 solar terms created by ancient Chinese to carry out agricultural activities. For the year 2020, the day of Guyu falls on April 19. (Photo by Wang Jilin/Xinhua)

Farmers pick tea leaves in Binhu District of Wuxi City, east China's Jiangsu Province, April 18, 2020. The upcoming Guyu, literally meaning "Rain of Millet", is the sixth of the 24 solar terms created by ancient Chinese to carry out agricultural activities. For the year 2020, the day of Guyu falls on April 19. (Photo by Hai Yueliang/Xinhua)