Local residents queue up for nucleic acid tests at a residential area in Ejina Banner of Alxa League, north China's Inner Mongolia Autonomous Region, Oct. 20, 2021. Photo: Xinhua

Photo taken on Oct. 20, 2021 shows a residential area under temporary lockdown due to COVID-19 control and prevention measures in Ejina Banner of Alxa League, north China's Inner Mongolia Autonomous Region.Photo: Xinhua

Staff members carry bags of daily necessities outside a supermarket in Ejina Banner of Alxa League, north China's Inner Mongolia Autonomous Region, Oct. 20, 2021.Photo: Xinhua

A medical worker disinfects facilities at a residential area in Ejina Banner of Alxa League, north China's Inner Mongolia Autonomous Region, Oct. 20, 2021.Photo: Xinhua

A medical worker takes a swab sample from a child for nucleic acid test at a residential area in Ejina Banner of Alxa League, north China's Inner Mongolia Autonomous Region, Oct. 20, 2021.Photo: Xinhua

A medical worker takes a swab sample from a resident for nucleic acid test at a residential area in Ejina Banner of Alxa League, north China's Inner Mongolia Autonomous Region, Oct. 20, 2021. Photo: Xinhua