/*
ID: 5ak0
PROG:
LANG: C++11
*/

#include <bits/stdc++.h>
#define fr first
#define sc second
#define pb push_back
#define mpr make_pair

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
const int INF = 1e9 + 7, MAXN = 1050;

int t, n;
string s[MAXN];

string nxt(string s){
    char bg = s[0];
    for (int i = 0; i < s.size() - 1; ++i)
        s[i] = s[i + 1];
    s[s.size() - 1] = bg;
    return s;
}

int main(){
    ios_base::sync_with_stdio(0);
    cin >> t;
    while (t--){
        cin >> n;
        for (int i = 1; i <= n; ++i){
            cin >> s[i];
            sort(s[i].begin(), s[i].end());
        }
        bool ok = 1;
        for (int i = 2; i <= n; ++i){
            for (int j = 0; j < s[i].size(); ++j){
                if (s[i - 1] + s[i] < s[i] + s[i - 1])
                    break;
                s[i] = nxt(s[i]);
            }
            if (s[i - 1] + s[i] > s[i] + s[i - 1])
                ok = 0;
        }
        cout << (ok ? "YES\n" : "NO\n");
    }
    return 0;
}