The friendship between Chinese President Xi Jinping and his old US friends started in Muscatine, Iowa and has lasted over 30 years. As an old Chinese saying goes, amity between the people holds the key to sound state-to-state relations. Only with sincere people-to-people exchanges can the tree of transnational friendship grow luxuriant. (Produced by Huang Jingjing, Gao Yuan and Zhu Yingqi)