Siobhan Lyons (R), president and CEO of Citizen Diplomacy International (CDI), speaks to Xinhua during an interview in Philadelphia, the United States, March 13, 2019. The amazing similarities in port, science and cultural diversity have helped fostering 40 years of sisterhood between the Chinese coastal city of Tianjin and the U.S. eastern city of Philadelphia. (Xinhua/Li Muzi)