用switch语句编写及格线

switch (score / 10) {
case 10:
case 9:
printf("成绩等级为：优秀\n");
break;
case 8:
printf("成绩等级为：良好\n");
break;
case 7:
printf("成绩等级为：中等\n");
break;
case 6:
printf("成绩等级为：及格\n");
break;
default:
printf("成绩等级为：不及格\n");
break;
}