Aerial photo taken on Aug. 6, 2021 shows citizens taking COVID-19 nucleic acid tests in Jiangdu District of Yangzhou, east China's Jiangsu Province. Jiangdu District of Yangzhou launched a second round of nucleic acid testing on Friday. (Photo by Yu Xing/Xinhua)
Aerial photo taken on Aug. 6, 2021 shows citizens lining up to take COVID-19 nucleic acid tests in Jiangdu District of Yangzhou, east China's Jiangsu Province. Jiangdu District of Yangzhou launched a second round of nucleic acid testing on Friday. (Photo by Yu Xing/Xinhua)
Medical workers and volunteers work on COVID-19 nucleic acid testing in Jiangdu District of Yangzhou, east China's Jiangsu Province, Aug. 6, 2021. Jiangdu District of Yangzhou launched a second round of nucleic acid testing on Friday. (Photo by Yu Xing/Xinhua)
Aerial photo taken on Aug. 6, 2021 shows citizens lining up to take COVID-19 nucleic acid tests in Jiangdu District of Yangzhou, east China's Jiangsu Province. Jiangdu District of Yangzhou launched a second round of nucleic acid testing on Friday. (Photo by Yu Xing/Xinhua)
A medical worker takes a swab sample from a citizen for COVID-19 nucleic acid testing in Jiangdu District of Yangzhou, east China's Jiangsu Province, Aug. 6, 2021. Jiangdu District of Yangzhou launched a second round of nucleic acid testing on Friday. (Photo by Yu Xing/Xinhua)
