#include <bits/stdc++.h>
#define ll long long
#define maxn 100005
#define slld(t) scanf("%lld",&t)
#define sd(t) scanf("%d",&t)
#define pd(t) printf("%d\n",t)
#define plld(t) printf("%lld\n",t)
#define fo(i,n) for(long long i=0;i<n;i++)
using namespace std;
struct node{
    int codi;
    int fr;
};
node fx[100000];
node fy[100000];
int arr1[100];
int arr2[100];
int arr3[100];
int arr4[100];
bool cmp(node a,node b){
    if(a.fr==b.fr)return a.codi<b.codi;
    return a.fr>b.fr ;

}
void solve(){
    int n;
    sd(n);


    fo(i,n){
       int x,y;
       sd(x);
       sd(y);
       x+=10000;
       y+=10000;
       arr1[i]=x;
       arr2[i]=y;
       arr3[i]=x;
       arr4[i]=y;


    }
    int x1,x2,y1,y2;
    sort(arr1,arr1+n);
     sort(arr2,arr2+n);
     x1=arr1[0];
     x2=arr1[n-1];
     y1=arr2[0];
     y2=arr2[n-1];

   // cout<<x1<<" "<<x2<<" "<<y1<<" "<<y2<<endl;
    bool an=1;
    fo(i,n){

        if(arr3[i]==x1 || arr3[i]==x2)continue;
        if(arr4[i]==y1 || arr4[i]==y2)continue;
       // cout<<i<<" "<<arr1[i]<<" "<<arr2[i]<<endl;
        an=0;
        break;

    }
    if(an){
        cout<<"YES"<<endl;
    }
    else cout<<"NO"<<endl;


}
int main(){
    int t;
    slld(t);
    while(t--)solve();
}