1944年9月，延安警备团战士张思德在大生产运动中因烧木炭而光荣牺牲。毛泽东主席在追悼张思德的大会上，曾作题为《为人民服务》的讲话。这是张思德（左）生前烧炭的情形。（新华社发）

    Undated photo shows Zhang Side (L) burn charcoal. Zhang Side, a soldier from Yan'an guard regiment, died of burning charcoal in the large-scale production campaign in Sept. 1944. Chairman Mao Zedong memorized Zhang Side by the subject entitled "Serving the People" speech.（Xinhua Photo）