Group 1 - The core message emphasizes the importance of commemorating revolutionary martyrs during the Qingming Festival, highlighting the historical significance of the Northeast Anti-Japanese United Army's struggle against Japanese invaders from 1931 to 1945 [1][28] - The "Mountain River Testimony" series aired on CCTV starting April 5, focusing on the sacrifices made by revolutionary heroes and the enduring spirit of resistance [1] - The memorial ceremony for martyr Yang Jingyu took place on April 3, attended by over 700 representatives from various sectors, reflecting the ongoing recognition of historical contributions in Jilin Province [3] Group 2 - The Red Stone Lazi Anti-Japanese Base was the first established by the Chinese Communist Party in Northeast China, marking a significant moment in the leadership of the anti-Japanese war [5] - Key figures such as Yang Jingyu and others were instrumental in organizing and leading guerrilla warfare against Japanese forces, creating multiple anti-Japanese units [7][8] - Yang Jingyu's leadership in the Northeast Anti-Japanese United Army was pivotal, especially during the intense battles against the Japanese Kwantung Army, which involved over 7,000 enemy troops [10][22] Group 3 - The sacrifices of anti-Japanese fighters, including the production of military supplies by women in the clothing factory, were crucial to the war effort, showcasing the collective contribution of various groups [12][14] - The story of An Shunhua, a notable figure who continued her work despite personal losses, exemplifies the resilience and dedication of those involved in the anti-Japanese struggle [16][18] - The documentation of Yang Jingyu's final battles reveals the extreme conditions faced by the anti-Japanese forces, culminating in his heroic sacrifice at the age of 35 [24][26] Group 4 - The total casualties among the Northeast Anti-Japanese United Army and the Northeast Volunteer Army during the 14-year war exceeded 330,000, with significant losses among higher-ranking officers [28] - The commemoration of martyrs serves not only as a remembrance of their sacrifices but also as a source of inspiration for future generations, reinforcing the spirit of resilience and patriotism [28]