#include<iostream>
#include<unordered_set>
#include<vector>
using namespace std;
using ll = long long;
const int N = 1e5 + 9;
unordered_set<int> st;
vector<int> v;
vector<int> uniqueElements;

void solve()
{
	st.clear();
	v.clear();
	uniqueElements.clear();
	ll n; cin >> n;
	int i = 0;
	while (n--)
	{
		int x; cin >> x;
		v.push_back(x);
	}
	for (const auto& element : v)
	{
		if (st.insert(element).second)
		{
			uniqueElements.push_back(element);
		}
	}

	for (const auto& i : uniqueElements) cout << i << " ";
	cout << '\n';
}

int main()
{
	ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	ll t; cin >> t;
	while (t--) solve();
	return 0;
}