A medical worker collects a swab sample from a child at a COVID-19 testing site in Baiwangzhuang Village of Jingxing County, Shijiazhuang, capital of north China's Hebei Province, Jan. 20, 2021. Shijiazhuang on Wednesday launched the third round of citywide nucleic acid testing, which is going to be completed within three days. (Xinhua/Jin Liangkuai)
