C语言 学生成绩管理系统答:printf("%10s%10s%8s%8s%8s%10s\n","学号","姓名","成绩","成绩","成绩","平均成绩"); printf("---\n"); printf("%10s%10s%8.2f%8.2f%8.2f%10.2f\n",students[index].ID,students[index].Name, students[index].Mark1,students[index].Mark2,students[index].Mark3,students[index].Av...