import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        
Scanner in = new Scanner(System.in);
        int q = in.nextInt();
        int[] a = new int[q];
        int x = 0;
        int y = 0;
        int prev_x = 0;
        int prev_y = 0;
        for(int i=0; i<q; i++){
            int n =in.nextInt();
            for(int j=0; j<n; j++){
                x =in.nextInt();
                y =in.nextInt();
                if(!(prev_x==0 && prev_y==0)){
                   int diff_x = Math.abs(prev_x-x);
                   int diff_y = Math.abs(prev_y-y);
                   
                   if(diff_x!=diff_y){
                       System.out.println("NO");
                       return;
                   }
                }
                prev_x = x;
                prev_y = y;
            }
            System.out.println("YES");
        }
    }
}