运行结果出来问题，求看

Question

编译正常，运行结果一直是正常，不知道问题出在哪儿，可以帮忙看看吗

#include<stdio.h>
int main()
{
    int age;
    char gender;
    float BMI,height,weight;
    printf("please input your gender(M or F),age,height(m) and weight(kg)： \n");//M为男，F为女 
    scanf("%c %d %f %f",&gender,&age,&height,&weight);
    BMI=weight/(height*height);
    if(age>=18)
    {
       if(gender=='M')
       {
             if(BMI<18.5)
             printf("your weight:偏瘦");
          else if(18.5<BMI<24)
          printf("your weight:正常"); 
          else if(24<=BMI<28)
          printf("your weight:偏胖");
          else
          printf("your weight:非常肥胖"); 
       } 
        else
        {
            if(BMI<18)
            printf("your weight:偏瘦"); 
            else if(18<=BMI<23.5)
            printf("your weight:正常"); 
            else if(23.5<=BMI<27)
            printf("your weight:偏胖");
            else
            printf("your weight:非常肥胖");
        }          
    }
    else if(10<=age<18)
    {
        if(gender=='M')
        {
          if(BMI<17)
          printf("your weight:偏瘦");
          else if(17<=BMI<23.5)    
          printf("your weight:正常");
          else if(23.5<=BMI<27)
          printf("your weight:偏胖");
          else
          printf("your weight:非常肥胖");
        }
        else
        {
            if(BMI<16.5)
            printf("your weight:偏瘦");
            else if(16.5<=BMI<23)
            printf("your weight:正常");
            else if(23<=BMI<26.5)
            printf("your weight:偏胖");
            else
            printf("your weight:非常肥胖");
        }
    }
    else if(3<=age<10)
    {
        if(gender=='M')
        {
            if(BMI<19)
            printf("your weight:偏瘦");
            else if(19<=BMI<24.5)
            printf("your weight:正常");
            else if(24.5<=BMI<29)
            printf("your weight:偏胖");
            else
            printf("your weight:非常肥胖");
        }
        else
        {
            if(BMI<18.5)
            printf("your weight:偏瘦");
            else if(18.5<=BMI<24)
            printf("your weight:正常");
            else if(24<=BMI<28.5)
            printf("your weight:偏胖");
            else
            printf("your weight:非常肥胖");
        }
    }
    else
    {
        if(gender=='M')
        {
            if(BMI<19.5)
            printf("your weight:偏瘦");
            else if(19.5<=BMI<25)
            printf("your weight:正常");
            else if(25<=BMI<28.5)
            printf("your weight:偏胖");
            else
            printf("your weight:非常肥胖");
        }
        else
        {
            if(BMI<19)
            printf("your weight:偏瘦");
            else if(19<=BMI<25)
            printf("your weight:正常");
            else if(25<=BMI<28.5)
            printf("your weight:偏胖");
            else
            printf("your weight:非常肥胖");
        }
    }
    return 0;
}

Answer 1

18.5<BMI<24 关系运算符不能连着写，改成 BMI>18.5 && BMI<24
其他也一样改