A factory Workers' Theory Study Group (工人理论学习小组) preparing their bulletin board titled "Learn the theory of proletarian dictatorship well" (学好无产阶级专政的理论). Other bulletin boards and wall posters are made and discussed in the background, under a sign that reads "Earnestly study Chairman Mao's important instructions on theoretical issues" (认真学习毛主席关于理论问题的重要指示).