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


bool makeDesicion() 
{
	int n;
	cin >> n;

	int xArr[10], yArr[10];
	int xMax = INT_MIN, xMin = INT_MAX, yMax = INT_MIN, yMin = INT_MAX;

	for (int i = 0; i < n; ++i) 
	{
		int x, y;
		cin >> x >> y;

		if (x > xMax) 
		{
			xMax = x;
		}
		if (x < xMin) 
		{
			xMin = x;
		}
		if (y > yMax)
		{
			yMax = y;
		}
		if (y < yMin)
		{
			yMin = y;
		}

		xArr[i] = x;
		yArr[i] = y;
	}

	for (int i = 0; i < n; ++i) 
	{
		if (xArr[i] != xMax && xArr[i] != xMin && yArr[i] != yMax && yArr[i] != yMin) 
		{
			return false;
		}
	}

	return true;
}

int main() 
{
	int q;
	cin >> q;
	for (int i = 0; i < q; ++i) 
	{
		if (makeDesicion()) 
		{
			cout << "YES\n";
		}
		else 
		{
			cout << "NO\n";
		}
	}
}