#include <iostream>
#include <cstring>

using namespace std;

const int N = 2e5 + 3;

struct Node
{
	int el = 0;
	int af = 0;
}Hash[N];

int head[N];
int id;

void init()
{
	memset(Hash, 0x00, sizeof Hash);
	memset(head, 0x00, sizeof head);
	
	id = 0;
}

int HashFun(int x)
{
	return (x % N + N) % N;
}

void insert(int x)
{
	int idx = HashFun(x);
	
	Hash[++id].el = x;
	Hash[id].af = head[idx];
	head[idx] = id;
}

bool find(int x)
{
	int idx = HashFun(x);
	
	for(int sp = head[idx]; sp; sp = Hash[sp].af)
	{
		if(Hash[sp].el == x) return true;
	}
	
	return false;
}

int main()
{
	int T = 0; cin >> T;
	
	while(T--)
	{
		init();
				
		int n = 0; cin >> n;
		
		while(n--)
		{
			int num = 0; cin >> num;
			
			if(!find(num))
			{
				insert(num);
				
				cout << num << ' ';
			}
		}
		
		cout << endl;
	}
	
	return 0;
}