Commuters wearing face masks to protect against COVID-19 walk across a pedestrian bridge in the central business district in Beijing, Thursday, Dec. 23, 2021. China has ordered the lockdown of as many as 13 million people in neighborhoods and workplaces in the northern city of Xi'an following a spike in coronavirus cases, setting off panic buying just weeks before the country hosts the Winter Olympics. (AP Photo/Mark Schiefelbein)