#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>

int main() {

    int test,i,j,min=0,max=0,n,flag;
    scanf("%d",&test);
    while(test--)
        {
        scanf("%d",&n);
        int a[n],a1[n];
        for(i=0;i<n;i++)
            {
                scanf("%d",&a[i]);  
             scanf("%d",&a1[i]);
           if( a[i]<min)
               min = a[i];
             if( a1[i]>max)
               max = a1[i];
        }
        for(i=0;i<n;i++)
            {
            if(a[i] == min|| a[i] == max||a1[i] == min|| a1[i] == max )
                {
             flag=1;
            }
            else
                {
              flag=0;
            }
       
        }
        if(flag){  printf("YES\n");
        }else printf("NO");
    }
    
      return 0;
}