A medical worker takes a swab sample from a woman for COVID-19 test at a testing site in Nanjing, east China's Jiangsu Province, July 21, 2021. Nanjing, which has a population of more than 9.3 million, carried out citywide nucleic acid testing starting on Wednesday.(Photo: Xinhua)
Medical workers take swab samples from residents for COVID-19 test at a testing site in Nanjing, east China's Jiangsu Province, July 21, 2021. Nanjing, which has a population of more than 9.3 million, carried out citywide nucleic acid testing starting on Wednesday.(Photo: Xinhua)
People register for COVID-19 test at a testing site in Nanjing, east China's Jiangsu Province, July 21, 2021. Nanjing, which has a population of more than 9.3 million, carried out citywide nucleic acid testing starting on Wednesday.(Photo: Xinhua)
A medical worker takes a swab sample from an elderly man for COVID-19 test at a testing site in Nanjing, east China's Jiangsu Province, July 21, 2021. Nanjing, which has a population of more than 9.3 million, carried out citywide nucleic acid testing starting on Wednesday.(Photo: Xinhua)