#include <bits/stdc++.h>
#define pb(x) push_back(x)
#define bug cout<<"HERE"<<endl;
#define SSTR( x ) static_cast< std::ostringstream & >( \
        ( std::ostringstream() << std::dec << x ) ).str()
#define fast 	ios_base::sync_with_stdio(0); cin.tie(0);
#define FOR(i,n) for(int i=0;i<n;++i)
#define FOR2(i,x,n) for(int i=x;i<n;++i)
#define FOR3(i,n) for(int i=n;i>=0;++i)
#define inp freopen("input.txt", "r", stdin);
#define out freopen("output.txt", "w", stdout);
#define PI = acos(-1.0);
using namespace std;

typedef long long ll;
typedef vector<int> vi;

int q , n ;
int x [11] , y[11];
int main() {

	fast
	cin >> q ;
	while (q -- ) {
		cin >> n ;
		memset(x , 0 , sizeof(x));
		memset(y , 0 , sizeof(y));

		int maxX = - 100000 , minX = 100000;
		int maxY = - 100000 , minY = 100000;
		FOR (i , n) {
			cin >> x [i] >> y[i];
			maxX = max (maxX , x[i]);
			minX = min (minX , x[i]);
			maxY = max (maxY , y[i]);
			minY = min (minY , y[i]);
		}

		bool ok = 1 ;
		FOR (i , n) {
			ok = ok & (x[i] == minX || x[i] == maxX || y[i] == minY || y[i] == maxY);
		}

		if (ok) cout << "YES\n";
		else cout << "NO\n";
	}

	return 0;
}