#include <bits/stdc++.h>
using namespace std;
int main() {
    int q, n, x[10], y[10], i, flag, minx, miny, maxx, maxy;
    cin >> q;
    while (q--)
        {
        cin >> n;
        for (i=0; i<n; i++)
            cin >> x[i] >> y[i];
        minx = maxx = x[0];
        miny = maxy = y[0];
        for (i=1; i<n; i++)
            {
            if (x[i]<minx)
                minx = x[i];
            else if (x[i]>maxx)
                maxx = x[i];
            if (y[i]<miny)
                miny = y[i];
            else if (y[i]>maxy)
                maxy = y[i];
        }
        for (i=0; i<n; i++)
            {
            if (x[i]==minx || x[i]==maxx || y[i]==miny || y[i]==maxy)
                x[i] = 100000;
        }
        flag = 0;
        for (i=0; i<n; i++)
            {
            if (x[i]!=100000)
                {
                flag = 1;
                break;
            }
        }
        if (flag==1)
            cout << "NO\n";
        else
            cout << "YES\n";
    }
    return 0;
}