#include <iostream>
#include <map>

using namespace std;

const int N = 100010;

int main(){
    int t;
    scanf("%d", &t);
    while (t--){
        int n;
        scanf("%d", &n);
        map<int, int> mp;
        for (int i = 1; i <= n; i++){
            int x;
            scanf("%d", &x);
            mp[x] ++;
            if (mp[x] == 1) cout<<x<<' ';
        }
        cout<<endl;
    }
}