#include<bits/stdc++.h>
using namespace std;
map<string,int>mp;
int main(){
    string s;
    int n,m;
    cin>>n;
    while(n--){
        cin>>m;
        while(m--){
            cin>>s;
            if(!mp.found(s)){
                mp[s]=1;
                cout<<s<<" ";
            }
        }
        cout<<endl;
        map.clear();
    }
    return 0;
}