#include<bits/stdc++.h>
using namespace std;

//Constants
#define fori(x) for (unsigned int i = 0; i < x; i++)
#define forj(x) for (unsigned int j = 0; j < x; j++)
#define fork(x) for (unsigned int k = 0; k < x; k++)

#define forin(x, u) for (unsigned int i = 0; i < x; i++)
#define forde(x, u) for (unsigned int u = x - 1; u >= 0; u--)

#define DBG(x) cout << (x) << endl;
#define DBGT(x, t) cout << (t) << ": " << (x) << endl;
#define DBGVECTOR(x, t) cout << t << ": "; for (unsigned int z = 0; z < x.size(); z++) cout << x[z] << " "; cout << endl;
#define DBGARRAY(x, s, t) cout << t << ": "; for (unsigned int z = 0; z < s; z++) cout << x[z] << " "; cout << endl;
#define GETVEC(x, s) for (unsigned int z = 0; z < s; z++) { cin >> temp; x.push_back(temp); }

typedef long long ll;
typedef pair<long long, long long> pll;
typedef pair<double, double> pdd;
typedef pair<int, int> pii;
const ll mod7 = 1000000007;

//Structs

//Global Variables
ll A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z;
ll temp, temp2;
char tempChar;
string tempString;

//Function Declarations

int main()
{
    int minx = INT_MAX, maxx = INT_MIN, miny = INT_MAX, maxy = INT_MIN;
    cin >> N;
    bool acceptable = true;

    fori(N)
    {
        acceptable = true;
        cin >> B;
        forj(B)
        {
            cin >> temp >> temp2;
            if (j != 0)
            {
                if (!((temp == minx || temp == maxx) || (temp2 == miny || temp2 == maxy)))
                {
                    //DBGT(temp, "Broke");
                    acceptable = false;
                }
            }


            if (temp <= minx)
                minx = temp;
            if (temp2 <= miny)
                miny = temp2;

            if (temp >= maxx)
                maxx = temp;
            if (temp2 >= maxy)
                maxy = temp2;
        }
        if (acceptable)
            cout << "YES" << endl;
        else
            cout << "NO" << endl;
    }
}