#include<iostream>
#include<iomanip>
#include<math.h>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<string>
#include<queue>
#include<vector>
#include<set>
#include<stack>
#include<map>
#define maxn 10000000
#define mod 23333
#define base 233333
using namespace std;
vector<int>link[mod + 1];
long long  shu[maxn],ashu[maxn];
long long  n, m;
long long  get(int x) {
    return (x % base + base) % mod;
}
bool tget(int x) {
    for (int j = 0; j < link[get(x)].size(); ++j) {
        //cout << " " << link[get(x)][j] << " " << x << endl;
        if (link[get(x)][j] == x) {
            return false;
        }
    }
    return true;
}
int main(){
    cin >> n;
    while (n--) {
        int po = 0;
        memset(shu, 0, sizeof(shu));
        memset(ashu, 0, sizeof(ashu));
        memset(link, 0, sizeof(link));
        cin >> m;
        for (int i = 0; i < m; ++i) {
            cin >> shu[i];
            if (tget(shu[i]) ){
                cout << shu[i]<<" ";
                ashu[po++] = shu[i];
                link[get(shu[i])].push_back(shu[i]);
            }
        }
        cout << endl;
    }
    return 0;
}