#include <bits/stdc++.h>
using namespace std;
map<int,int> vis;
int n,m,t,a;
void work(){
	cin >> n;
	vis.clear();
	for(int i = 1;i <= n;i++){
		cin >> a;
		if(vis[a] == 0){
			cout << a << " ";
			vis[a] = 1;
		}
	}
	cout << "\n";
	return ;
}
int main(){
	int t;
	cin >> t;
	while(t--){
		work();
	}
	return 0;
}