#include<bits/stdc++.h>
#include<math.h>
#include<cmath>
using namespace std;
map<int, int> h;
int read(){// 快排
    int w=1,q=0;
	char ch=' ';
    while(ch!='-'&&(ch<'0'||ch>'9'))ch=getchar();
    if(ch=='-')w=-1,ch=getchar();
    while(ch>='0'&&ch<='9')q=q*10+ch-'0',ch=getchar();
    return w*q;
}
int main() {
	int t,n,x;
    t=read();
    for(int i=1;i<=t;i++){
    	h.clear();
        cin>>n;
        for(int j=1;j<=n;j++){
        	cin>>x;
            if(h[x]==0){
                cout<<x<<' ';
                h[x]=1;
            }
		}
        cout<<endl;
	} 
  return 0; 
}