A medical worker scans the nucleic acid samples collected from a mass testing at a lab in north China's Tianjin Municipality on Monday, Nov. 23, 2020. China has reported new coronavirus cases in the cities of Shanghai and Tianjin as it seeks to prevent small outbreaks from becoming larger ones. (Chinatopix via AP)

Use Information This content is intended for editorial use only.
For other uses, additional clearances may be required.