#include<bits/stdc++.h>
using namespace std;
int main()
{
    long long int t;
    cin>>t;
    while(t--)
    {
        long long int n,i,j,count1=0;
        cin>>n;
        vector<long long int>s1,s2;
        long long int arr1[2*n];
        for(i=0;i<2*n;i++)
        {
            cin>>arr1[i];

           if(arr1[i]%2==0)
           s1.push_back(i+1);
           else
           s2.push_back(i+1);
        }
        for(i=0;i<(int)s1.size()-1;i +=2)
        {
            if(count1<=n-2)
           {
               cout<<s1[i]<<" "<<s1[i+1]<<endl;
            count1++;

           }
           else
           break;

        }
        for(i=0;i<(int)s2.size()-1;i +=2)
        {
            if(count1<=n-2)
            {cout<<s2[i]<<" "<<s2[i+1]<<endl;
            count1++;}
            else
            break;
        }
    }
}