Evan Summer, a 78-year-old U.S. printmaking artist, learns the traditional Chinese qigong exercise Baduanjin during a flash mob event at Longhua Cultural and Sports Center in Longhua District on Saturday. Baduanjin, or Eight Pieces of Brocade, is one of the most ancient forms of Chinese qigong (a system of deep-breathing exercises) with a history of more than 800 years. It is renowned for its health benefits, combining gentle movements with breath control.Liu Xudong