//UVA1595Symmetry
#include<cstdio>
#include<iostream>
#include<map>
#include<string>
#include<cstring>
using namespace std;
const int MAXN = 2000;
typedef pair<double, double> LL;
LL dot_pair[MAXN];
map<LL, int> Match;
int main() {

	int kase = 0;
	scanf("%d", &kase);
	while(kase--) {
		int n = 0;
		scanf("%d", &n);
		double sum = 0;
		for(int i = 0; i < n; i++) {
			double a, b;
			scanf("%lf%lf", &a, &b);
			dot_pair[i].first = a;
			//printf("a = %.0f\n",  a);
			sum += a;
			dot_pair[i].second = b;
			Match[dot_pair[i]] = 1;
		}
		double aver = sum / n;
		//printf("aver = %.0lf\n", aver);
	    int i = 0;
		for(i = 0; i < n; i++) {
			double a = 2 * aver - dot_pair[i].first;
			double b = dot_pair[i].second;
			LL tmp_pair(a, b);
		//	printf("i = %d : (%.0lf, %.0lf)  (%.0lf, %.0lf)\n", i, dot_pair[i].first, dot_pair[i].second, tmp_pair.first, tmp_pair.first);
			if(!Match.count(tmp_pair)) break;
		}
		puts(i == n ? "YES" : "NO");
	}
    return 0;
}
/*

3
5
-2 5
0 0
6 5
4 0
2 3
4
2 3
0 4
4 0
0 0
4
5 14
6 10
5 10
6 14

*/