#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
using namespace std;
int eightBit[10][2];


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */  
    int q,n,i,j;
    string tot;
    cin >>q;
    for (i=0; i<q; i++)
        {
        cin >> n;
        for (j=0; j<n; j++)
            {
            for(int k=0; k<2; ++k)
            {
             int tri [n][2];
                cin >> eightBit[j][k];
                tri[j][k]=eightBit[j][k];
                if ((tri[k][j+1]==tri[k+1][j]) and (tri[k][j]!=tri[k+1][j+1]))
                {tot ="NO";}
                else
                {tot = "YES";}
            }
        } cout << tot << endl;
    }
    return 0;
}