#include<stdio.h>
main()
{
int age;
printf("please input your age:");
scanf("%d",&age);
switch(age)
{
case 2:
printf("enter Lower class\n");
break;
case 3:
printf("enter Lower class\n");
break;
case 4:
printf("enter Middle class\n");
break;
case 5:
printf("enter Higher class\n");
break;
case 6:
printf("enter Higher class\n");
break;
default:
printf("输入错误！\n");
break;
}
return 0;
}

这个更简单~~~~~~~~~~~~~~~~
#include<stdio.h>
main()
{
int age;
printf("please input your age:");
scanf("%d",&age);
switch(age)
{
case 2:
case 3:
printf("enter Lower class\n");
break;
case 4:
printf("enter Middle class\n");
break;
case 5:
case 6:
printf("enter Higher class\n");
break;
default:
printf("输入错误！\n");
break;
}
return 0;
}