Xu Jiayu, Yan Zibei, Zhang Yufei and Yang Junxuan (L to R) of Jiangsu-Zhejiang-Shandong-Hubei united team enter before the mixed 4X100m medley relay final at the 2021 Chinese National Swimming Championships in Qingdao, east China's Shandong Province, May 7, 2021. (Xinhua/Xu Chang)
