People receive nucleic acid tests at a temporary COVID-19 testing site at an expressway toll station in Harbin, Northeast China's Heilongjiang province, March 14, 2022. [Photo/Xinhua]
Photo taken on March 18, 2022 shows a view of mobile testing labs for COVID-19 at an exhibition and sports center in Harbin, Northeast China's Heilongjiang province. [Photo/Xinhua]
A medical worker tests equipments at a mobile testing lab for COVID-19 in Harbin, Northeast China's Heilongjiang province, March 18, 2022. [Photo/Xinhua]
People receive nucleic acid tests at a temporary COVID-19 testing site at an expressway toll station in Harbin, Northeast China's Heilongjiang province, March 14, 2022. [Photo/Xinhua]
A medical worker takes a swab sample from a resident for nucleic acid test at a COVID-19 testing site in Harbin, Northeast China's Heilongjiang province, March 15, 2022. [Photo/Xinhua]
A medical worker takes a swab sample from a resident for nucleic acid test at a COVID-19 testing site in Harbin, Northeast China's Heilongjiang province, March 16, 2022. [Photo/Xinhua]
A medical worker takes a swab sample from a resident for nucleic acid test at a COVID-19 testing site in Harbin, Northeast China's Heilongjiang province, March 18, 2022. [Photo/Xinhua]