马伟、杨洋和黄海(均为化名)是某小学五年级四班学生。某日下午课间休息时,同学们像往常一样,在一起嬉笑打闹。当时,马伟坐在教室第一排位置上,正回头与同学说话,杨洋正面对马伟无所事事地玩弄着铅笔刀,黄海则在杨洋身后和几个学生推着玩。就在这时,不幸的事情发生了。黄海在杨 Ma Wei Yang Yang and Huang Hai (both are pseudonyms) is a fifth grade fifth grade four students. One afternoon afternoon break, classmates, as usual, laughing together slapstick. At that time, Ma Wei sat in the classroom in the first row position, is looking back with his classmates, Yang Yang is facing Ma Wei doing nothing to play with a pencil sharpener, Yang in the Yang Yang and several students behind playing. Just then, the unfortunate thing happened. Yellow Sea in Yang