Learn from the good cadres as well as comrades who are boundlessly loyal to Chairman Mao's revolutionary road; never forget the class hardships; boundlessly love Chairman Mao
向无限忠于毛主席革命路线的好干部门合同志学习; 终生不忘阶级苦; 无限热爱毛主席
Xiang wuxian zhongyu Mao zhuxi geming luxian de hao ganbumen he tongzhi xuexi; zhongsheng bu wang jiejiku; wuxian re'ai Mao zhuxi
From (incomplete) series on the martyr Men He (门合, 1928-1967).
The text on the blackboard: "Chairman Mao, long long live!" (毛主席万万岁!).
The text in a frame, left in the background, is a "Quotation from Chairman Mao" (毛主席語錄).