#include <iostream>
#include <set>
#include <vector>
using namespace std;

int main()
{
  int T;
  cin >> T;
  for (int i = 0; i < T; i++)
  {
    int n;
    cin >> n;
    set<int> nums;
    vector<int> output;
    int a;
    for (int j = 0; j < n; j++)
    {
      cin >> a;
      if (nums.count(a) == 0)
        {
          output.push_back(a);
          nums.insert(a);
        }
    }

    for (int j = 0; j < output.size(); j++)
    {
      cout << output[j];
      if (j != output.size() - 1)
    cout << " ";
    }
    cout << endl;
  }
  return 0;
}