What do you usually do in the school playground? 上体育课，做课间操，玩各种户外游戏？Some kids in Chongqing grow vegetables in the playground! 一个晴朗的下午，重庆北碚区朝阳小学南校区400多名学生提着水桶，拿着锄头和铲子来到了操场上。There is a new piece of farmland in a corner of the playground...