#include<bits/stdc++.h>

using namespace std;

#define MOD 10007

#define MAXN 50010

int T,n,len,i,x;

int a[MAXN];

vector<int> e[MOD];

inline void Clear() {

        int i;

        for (i = ; i < MOD; i++) e[i].clear();

}

inline bool Find(int x) {

        int i,h;

        if (x < ) h = (-x) % MOD;

        else h = x % MOD;

        for (i = ; i < e[h].size(); i++) {

                if (e[h][i] == x) return true;

        }

        return false;

}

inline void ins(int x) {

        int h;

        if (x < ) h = (-x) % MOD;

        else h = x % MOD;

        e[h].push_back(x);

}

int main() {

        scanf("%d",&T);

        while (T--) {

                len = ;

                scanf("%d",&n);

                Clear();

                for (i = ; i <= n; i++) {

                        scanf("%d",&x);

                        if (!Find(x)) {

                                a[++len] = x;

                                ins(x);

                        }

                }

                for (i = ; i < len; i++) printf("%d ",a[i]);

                printf("%d\n",a[len]);

        }

        return ;

}