Villagers arrange paddy seedlings in a field in Yinan County, Linyi City of east China's Shandong Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Du Yubao)

Villagers pick blueberries in Jiangziya Village, Zaozhuang City of east China's Shandong Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Li Zongxian)

A farmer plows the field in Mafeng Village, Hezhou City of south China's Guangxi Zhuang Autonomous Region, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Liao Zuping)

Villagers harvest wheat in Luojiatun Village, Tangshan City of north China's Hebei Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Wang Aijun)

A farmer plows in field in Mafeng Village, Hezhou City of south China's Guangxi Zhuang Autonomous Region, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Liao Zuping)

Villagers arrange paddy seedlings in a field in Yinan County, Linyi City of east China's Shandong Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Du Yubao)

A farmer harvests blueberries in Shaocha Village, Danzhai County of southwest China's Guizhou Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Huang Xiaohai)

Villagers sow seeds in the field in Maoguan Village, Weining County of Bijie City, southwest China's Guizhou Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Tao Liang)

Villagers dry wheat in Donggaozhuang Village, Tangshan City of north China's Hebei Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Dong Jun)

A villager sows seeds in the field in Maoguan Village, Weining County of Bijie City, southwest China's Guizhou Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Tao Liang)

A villager works in the field in Maoguan Village, Weining County of Bijie City, southwest China's Guizhou Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Tao Liang)

A villager works in the field in Shuichao Village, Weining County of Bijie City, southwest China's Guizhou Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Tao Liang)

Villagers transplant pepper seedlings in Shiban Town, Zunyi City of southwest China's Guizhou Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Xiang Dingjie)

Villagers harvest wheat in Xiaolizhuang Village, Tangshan City of north China's Hebei Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Dong Jun)

Villagers sow seeds in the field in Maoguan Village, Weining County of Bijie City, southwest China's Guizhou Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Tao Liang)

A villager harvests cabbage mustard in Xiejiawan Village, Zhangye City of northeast China's Gansu Province, June 21, 2019. Friday marks the Summer Solstice, the 10th solar term on the Chinese lunar calendar. Farmers across the country are busy with works in the fields. (Xinhua/Wang Jiang)