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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int t,slope;
    cin>>t;
    for(int r=0;r<t;r++)
        {
        int n;
        cin>>n;
        int a[n][2];
        int i,j;
        for(i=0;i<n;i++)
            {
            for(j=0;j<2;j++)
            cin>>a[i][2];
        }
        int f=1;
        for(i=0;i<n-1;i++)
           { for(j=0;j<2;j++)
            if(a[i][j]!=a[i+1][j])
            {
            f=0;
               break;
        }
            if(f==0)
                break;
           }
        if(f==1)
            {
            cout<<"YES"<<endl;       
        }
        else{
            f=1;
            slope=(a[i+1][1]-a[i][1])/(a[i+1][0]-a[i][0]);
            for(i=0;i<n-1;i++)
                {
                if(slope!=(a[i+1][1]-a[i][1])/(a[i+1][0]-a[i][0]))
                    {
                    f=0;
                    break;
                }
                }
            if(f==0)
                cout<<"YES\n";
            else
                cout<<"NO\n";
            }
        }
    return 0;
}