-- Xi'an, capital city of northwest China's Shaanxi Province, has basically stopped the spread of COVID-19 in communities one month after the resurgence of the epidemic hit the city, thanks to stringent containment measures such as city-level lockdown and rounds of mass nucleic acid testing.The number of confirmed cases in Xi'an rose by more than 150 per day for a week in late December, and the virus has spread to other cities and provinces.