An empty square is seen in the Old Town in Warsaw, Poland, Dec. 29, 2020. Poland on Monday imposed a nationwide lockdown from Dec. 28 to Jan. 17 in an effort to contain the COVID-19 pandemic. (Photo by Jaap Arriens/Xinhua)

A woman wearing a face mask walks in the Old Town in Warsaw, Poland, Dec. 29, 2020. Poland on Monday imposed a nationwide lockdown from Dec. 28 to Jan. 17 in an effort to contain the COVID-19 pandemic. (Photo by Jaap Arriens/Xinhua)

A woman wearing a face mask walks on an empty street in the Old Town in Warsaw, Poland, Dec. 29, 2020. Poland on Monday imposed a nationwide lockdown from Dec. 28 to Jan. 17 in an effort to contain the COVID-19 pandemic. (Photo by Jaap Arriens/Xinhua)