#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

int x[1000];
int y[1000];
int q, n, i;
bool t;
struct p{
  int x, y;
  p operator = (const p&a ){
      x = a.x;
      y = a.y;
      return *this;
  }
}a[10];
p v1, v2, v3, v4;
int main() {
    cin>>q;
    while(q--){
        cin>>n;
        t = true;
        for(i = 0; i < n; i++) cin>>a[i].x>>a[i].y;
        v1 = v2 = v3 = v4 = a[0];
        for(i = 0; i < n; i++){
            if (v1.x > a[i].x) v1 = a[i];
            if (v1.x == a[i].x){
                if(v1.y < a[i].y) v1 = a[i];
            }
            if (v3.x < a[i].x) v3 = a[i];
            if (v3.x == a[i].x){
                if(v3.y > a[i].y) v3 = a[i];
            }
        }
        for(i = 0; i < n; i++){
            if( a[i].x == v1.x || a[i].y == v1.y || a[i].x == v3.x || a[i].y == v3.y ) t = true;
            else t = false;
        }
        cout<<(t ? "YES" : "NO")<< endl;
    }
    return 0;
}