#include <bits/stdc++.h>
using namespace std;
void dfs(int u, int p, vector<vector<long long int> > &g,
         vector<long long int> &vis, vector<long long int> &subt) {
  if (vis[u] != -1) return;
  vis[u] = p;
  subt[u] = 1;
  for (auto &z : g[u]) {
    if (z == p) continue;
    dfs(z, u, g, vis, subt);
    subt[u] += subt[z];
  }
  return;
}
int main() {
  long long int tt = 1, n, q, m, l, r, c, i, j, k, w;
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  cin >> tt;
  long long int ans = 0;
  for (int _ = 1; _ <= tt; _++) {
    cin >> n;
    vector<vector<long long int> > g(n);
    for (i = 0; i < n - 1; i++) {
      cin >> l >> r;
      l--, r--;
      g[l].push_back(r);
      g[r].push_back(l);
    }
    vector<long long int> vis(n, -1), subt(n, 0);
    dfs(0, -1, g, vis, subt);
    vector<long long int> cent;
    long long int mn = n + 1;
    for (i = 0; i < n; i++) {
      long long int mx = n - subt[i];
      for (auto &z : g[i]) {
        if (z == vis[i]) continue;
        mx = max(mx, subt[z]);
      }
      if (mn > mx) {
        mn = mx;
        cent.clear();
      }
      if (mn == mx) {
        cent.push_back(i);
      }
    }
    if ((long long int)(cent).size() == 1) {
      cout << 1 << ' ' << g[0][0] + 1 << "\n";
      cout << 1 << ' ' << g[0][0] + 1 << "\n";
    } else {
      assert((long long int)(cent).size() == 2);
      l = cent[0];
      r = cent[1];
      c = -1;
      for (auto &z : g[l]) {
        if (z != r) {
          c = z;
          break;
        }
      }
      l++, r++, c++;
      cout << l << ' ' << c << "\n";
      cout << r << ' ' << c << "\n";
    }
  }
}
