Children learn to tie knot under the guidance of naval soldiers during an open day event at a port in east China's Shanghai, April 23, 2024. The Chinese People's Liberation Army Navy holds open day events in Shanghai on Tuesday to mark the 75th anniversary of its founding. Visitors could tour the guided-missile destroyer Zibo and hospital ship "Peace Ark" at the event. (Xinhua/Fang Zhe)

This aerial drone photo shows the guided-missile destroyer Zibo mooring at a port in east China's Shanghai, April 22, 2024. The Chinese People's Liberation Army Navy holds open day events in Shanghai on Tuesday to mark the 75th anniversary of its founding. Visitors could tour the guided-missile destroyer Zibo and hospital ship "Peace Ark" at the event. (Xinhua/Fang Zhe)

A primary school student tries the sextant under the guidance of naval soldier during an open day event at a port in east China's Shanghai, April 23, 2024. The Chinese People's Liberation Army Navy holds open day events in Shanghai on Tuesday to mark the 75th anniversary of its founding. Visitors could tour the guided-missile destroyer Zibo and hospital ship "Peace Ark" at the event. (Xinhua/Fang Zhe)

Students perform during an open day event at a port in east China's Shanghai, April 23, 2024. The Chinese People's Liberation Army Navy holds open day events in Shanghai on Tuesday to mark the 75th anniversary of its founding. Visitors could tour the guided-missile destroyer Zibo and hospital ship "Peace Ark" at the event. (Xinhua/Fang Zhe)

People watch a performance staged by naval soldiers during an open day event at a port in east China's Shanghai, April 23, 2024. The Chinese People's Liberation Army Navy holds open day events in Shanghai on Tuesday to mark the 75th anniversary of its founding. Visitors could tour the guided-missile destroyer Zibo and hospital ship "Peace Ark" at the event. (Xinhua/Fang Zhe)

This aerial drone photo shows the guided-missile destroyer Zibo (L) and the naval hospital ship "Peace Ark" mooring at a port in east China's Shanghai, April 22, 2024. The Chinese People's Liberation Army Navy holds open day events in Shanghai on Tuesday to mark the 75th anniversary of its founding. Visitors could tour the guided-missile destroyer Zibo and hospital ship "Peace Ark" at the event. (Xinhua/Fang Zhe)

This aerial drone photo shows the naval hospital ship "Peace Ark" mooring at a port in east China's Shanghai, April 22, 2024. The Chinese People's Liberation Army Navy holds open day events in Shanghai on Tuesday to mark the 75th anniversary of its founding. Visitors could tour the guided-missile destroyer Zibo and hospital ship "Peace Ark" at the event.