为什么输出结果为0？？（用的是dev c++)

Question

include <stdio.h>

int main()
{

char sex;
char sports; 
char diet;
float faheight;
float moheight;
float myheight;
printf("Are you (g)or(b)?");
scanf("%ls", &sex);
printf("喜欢体育锻炼(y)or不喜欢(n)");
scanf("%ls", &sports);
printf("有良好的卫生习惯(y)or(n)");
scanf("%ls", &diet);
printf("你父亲的身高");
scanf("%f", &faheight);
printf("你母亲的身高");
scanf("%f", &moheight);
if(sex=='b'||sex=='B')
{
    myheight=((faheight+moheight)*0.54);
}
if(sex=='g'||sex=='G')
{
    myheight=((faheight*0.923+moheight)/2.0);
}
if(sports=='y'||sports=='Y')
{
    myheight=(myheight*(1+0.02));    
}
if(diet=='y'||diet=='Y')
{
    myheight=(myheight*(1+0.015));    
}
printf("Your future height will be %.2f(cm)\n",myheight);
return 0;

}

Answer 1

"%ls" => "%c"

Answer 2

不是很懂，是直接在"%ls"后面加=> "%c"吗？？