A medical worker collects a swab sample from a resident at a COVID-19 testing site in Xining, Northwest China's Qinghai province, Nov 2, 2021. Xining has set up 121 testing sites in Chengxi district for massive COVID-19 nucleic acid testing. [Photo/Xinhua]
Aerial photo taken on Nov 2, 2021 shows a COVID-19 testing site in Xining, Northwest China's Qinghai province. Xining has set up 121 testing sites in Chengxi district for massive COVID-19 nucleic acid testing. [Photo/Xinhua]
Aerial photo taken on Nov 2, 2021 shows a COVID-19 testing site in Xining, Northwest China's Qinghai province. [Photo/Xinhua]
A medical worker collects a swab sample from a resident at a COVID-19 testing site in Chengxi district of Xining, Northwest China's Qinghai province, Nov 2, 2021. [Photo/Xinhua]
A medical worker collects a swab sample from a resident at a COVID-19 testing site in Chengxi district of Xining, Northwest China's Qinghai province, Nov 2, 2021. [Photo/Xinhua]
A medical worker collects a swab sample from a resident at a COVID-19 testing site in Chengxi district of Xining, Northwest China's Qinghai province, Nov 2, 2021. [Photo/Xinhua]
Residents scan a QR code to have their personal information registered at a COVID-19 testing site in Chengxi district of Xining, Northwest China's Qinghai province, Nov 2, 2021. [Photo/Xinhua]
A medical worker collects a swab sample from a child at a COVID-19 testing site in Chengxi district of Xining, Northwest China's Qinghai province, Nov 2, 2021. [Photo/Xinhua]