百分制成绩五级分制输出--二次作业

#include<studio.h>
main{
   float s,A,B,C,D,E
  printf("%f/n",s)
   if(s>=90<=100)
      scanf("%f/n",A);
   else if(80<=s<90)
      scanf("%f/n",B);
   else if(70<=s<80)
      scanf("%f/n",C);
   else if(60<=s<70)
      scanf("%f/n",D);  
   else 
      scanf("%f/n",E);
}
#include<studio.h>
main{
   float s,A,B,