Complex sentence: During Mao Zedong's early years, he lived in Changsha, he and his friends He Shuheng, Xiao Zisheng, Cai Hesen, Xiao San and Xiang Jingyu walked on the isle and swam in Xiang River.
Split into simpler sentences: During Mao Zedong's early years, he lived in Changsha. He and his friends He Shuheng, Xiao Zisheng, Cai Hesen, Xiao San and Xiang Jingyu would swim in the Xiang River.