A staff member prepares to work at a temporary laboratory for nucleic acid testing at a stadium in Nanjing, capital of east China's Jiangsu Province, July 27, 2021. Nanjing started building the six "Falcon" testing labs on Sunday. Three of the labs went into operation on Monday morning, and the others will be completed by the end of Tuesday. When all six labs are in use, 180,000 sample tubes can be tested daily, and if mixed sample tests are carried out, 1.8 million people can be screened every day. (Xinhua/Li Bo)