#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
int check(int a[],int b[],int n)
{
    int x=0,y=0,i;
    for(i=2;i<n;i++)
    {
        //flag=1;
        x=(b[i]-b[i-1]);
        y=(a[i]-a[i-1]);
        if(x!=0&&y!=0)
            {
            return 0;
             //break;
        }
    }
   /*x=b[n]-b[1];
   y=a[n]-a[1];
    if(x!=0||y!=0)
        return 1;*/
     //   flag=0;
    return 1;
}
int main() {

    /* Enter your code here. Read input from STDIN. Print output to STDOUT */    
    int q,n;
    scanf("%d",&q);
    while(q--)
        {
        scanf("%d",&n);
        int x[n+1],y[n+1],i,flag=0;
        for(i=1;i<=n;i++)
            scanf("%d %d",&x[i],&y[i]);
       flag=check(x,y,n);
        if(flag==1)
            printf("YES\n");
        else
            printf("NO\n");
    }
    return 0;
}