#include <bits/stdc++.h>
using namespace std;
using namespace chrono;
const long long MOD = 1000000007;
const long long N = 300005;
const long long inf = 10000000000000000;
const double PI = 3.141592653589793238462;
void print(vector<long long> v) {
  long long i;
  for (i = 0; i < v.size(); i++) cout << v[i] << " ";
  cout << "\n";
}
void print(vector<pair<long long, long long> > v) {
  long long i;
  for (i = 0; i < v.size(); i++) {
    cout << v[i].first << " " << v[i].second << "\n";
  }
}
vector<long long> read(long long n) {
  long long i;
  vector<long long> arr(n, 0);
  for (i = 0; i < n; i++) cin >> arr[i];
  return arr;
}
vector<long long> read(long long n, long long k) {
  long long i;
  vector<long long> arr(n + k, 0);
  for (i = k; i < n + k; i++) cin >> arr[i];
  return arr;
}
bool isEven(long long n) { return n % 2 == 0; }
bool isOdd(long long n) { return n % 2 != 0; }
vector<long long> adj[N];
vector<long long> vis(N, 0);
vector<long long> mid;
long long n;
long long m;
long long dfs(long long cur, long long par) {
  vis[cur] = 1;
  long long ct = 0;
  for (auto next : adj[cur]) {
    if (!vis[next]) {
      ct += dfs(next, cur);
    }
  }
  if (ct == m) {
    mid.push_back(cur);
    mid.push_back(par);
  }
  return 1 + ct;
}
void solve() {
  long long t = 1, cs = 1;
  cin >> (t);
  while (t--) {
    long long i, j, k, p, q, x, y, a, b, l, r;
    cin >> n;
    mid.clear();
    for (i = 1; i < n + 1; i++) {
      adj[i].clear();
      vis[i] = 0;
    }
    long long x1 = -1, y1 = -1;
    for (i = 0; i < n - 1; i++) {
      cin >> x >> y;
      if (x1 == -1) {
        x1 = x;
        y1 = y;
      }
      adj[x].push_back(y);
      adj[y].push_back(x);
    }
    if (isOdd(n)) {
      cout << x1 << " " << y1 << "\n" << x1 << " " << y1 << "\n";
      continue;
    }
    m = n / 2 - 1;
    dfs(1, -1);
    if (mid.empty()) {
      cout << x1 << " " << y1 << "\n" << x1 << " " << y1 << "\n";
      continue;
    }
    long long fir = mid[0], sec = mid[1];
    for (auto next : adj[fir]) {
      if (next != sec) {
        y1 = next;
        break;
      }
    }
    x1 = fir;
    long long x2 = sec, y2 = y1;
    cout << x1 << " " << y1 << "\n" << x2 << " " << y2 << "\n";
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  auto start = high_resolution_clock::now();
  solve();
  long long i, j, k, n, m, p, q, x, y, a, b, l, r;
  auto stop = high_resolution_clock::now();
  auto duration = duration_cast<microseconds>(stop - start);
  return 0;
}
