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    Last week, our class was on duty for student self-management. On the first day, I was shocked to see so much leftover food thrown away by students. What a waste! Being concerned about it, my classmates and I had a heated discussion on how to solve the problem. Finally, we all (agree) that the wall newspaper would be the best choice. The next day, we put our idea into reality. Towards lunch time, we put a wall newspaper outside the school cafeteria, calling on students not to waste food. Many students gathered around to read and expressed their support. To my great delight, there were changes soon. In the cafeteria, I found the trays returned after lunch all empty without any leftover. Food(save) and the dining hall was cleaner.