Photo taken with a mobile phone shows tea fields in Songyan Town of Yuqing County, southwest China's Guizhou Province, March 31, 2018. Farmers are busy in harvesting tea leaves ahead of the Qingming Festival to produce the Mingqian (literally "pre-Qingming") tea, which are made of the very first tea sprouts in spring and considered to be of high quality. (Xinhua/Yang Wenbin)

A worker processes tea leaves in Songyan Town of Yuqing County, southwest China's Guizhou Province, March 31, 2018. Farmers are busy in harvesting tea leaves ahead of the Qingming Festival to produce the Mingqian (literally "pre-Qingming") tea, which are made of the very first tea sprouts in spring and considered to be of high quality. (Xinhua/Yang Wenbin)

A farmer picks tea leaves in Songyan Town of Yuqing County, southwest China's Guizhou Province, March 31, 2018. Farmers are busy in harvesting tea leaves ahead of the Qingming Festival to produce the Mingqian (literally "pre-Qingming") tea, which are made of the very first tea sprouts in spring and considered to be of high quality. (Xinhua/Yang Wenbin)

Farmers pick tea leaves in Songyan Town of Yuqing County, southwest China's Guizhou Province, March 31, 2018. Farmers are busy in harvesting tea leaves ahead of the Qingming Festival to produce the Mingqian (literally "pre-Qingming") tea, which are made of the very first tea sprouts in spring and considered to be of high quality. (Xinhua/Yang Wenbin)

A worker processes tea leaves in Songyan Town of Yuqing County, southwest China's Guizhou Province, March 31, 2018. Farmers are busy in harvesting tea leaves ahead of the Qingming Festival to produce the Mingqian (literally "pre-Qingming") tea, which are made of the very first tea sprouts in spring and considered to be of high quality. (Xinhua/Yang Wenbin)

Farmers pick tea leaves in Songyan Town of Yuqing County, southwest China's Guizhou Province, March 31, 2018. Farmers are busy in harvesting tea leaves ahead of the Qingming Festival to produce the Mingqian (literally "pre-Qingming") tea, which are made of the very first tea sprouts in spring and considered to be of high quality. (Xinhua/Yang Wenbin)

Farmers pick tea leaves in Songyan Town of Yuqing County, southwest China's Guizhou Province, March 31, 2018. Farmers are busy in harvesting tea leaves ahead of the Qingming Festival to produce the Mingqian (literally "pre-Qingming") tea, which are made of the very first tea sprouts in spring and considered to be of high quality. (Xinhua/Yang Wenbin)