Lin Xu (rear), wife of Chen Sitan, teaches kids martial arts at Sitan Tai Chi and Martial Arts, a martial art school in Syosset of New York, the United States, Nov. 20, 2019. The ancient Chinese martial art Tai Chi has increasingly become a form of life for many New Yorkers, thanks to the efforts made by former world martial art champion Chen Sitan and his wife Lin Xu. (Xinhua/Wang Ying)