//....SARANSH GUPTA....\  


#include<bits/stdc++.h>
using namespace std;
#define int long long
#define fo(p,n) for(int i=p;i<n;i++)
#define FIO ios_base::sync_with_stdio(false);   cin.tie(NULL);   cout.tie(NULL);
#define endl "\n" 
#define mp make_pair
#define pb push_back
#define mod 1000000007


const int N=2e5+5;
int n;
int a[N];
signed main()
{
    FIO
    int t;
    t=1;
    cin>>t;
    while(t--)
    {
        cin>>n;
        n*=2;
        fo(0,n)
        {
            cin>>a[i];
        }
        sort(a,a+n);
        int f=0;    
        fo(0,n-1)
        {
            int x=a[n-1]+a[i];
            int temp=x;
            unordered_map<int,int> m;
            for(int j=0;j<n;j++)
            {
                m[a[j]]++;
            }
            int j=n-1;
            int count=0;
            while(1)
            {
                while(!m[a[j]])
                {
                    j--;
                }
                m[a[j]]--;
                   
                if(m[x-a[j]])
                {
                    m[x-a[j]]--;
                    x=a[j];
                    j--;
                    count+=2;
                }
                else
                {
                    break;
                }
                if(count==n)
                break;   
            }
            if(count==n)
            {
                f=1;
                cout<<"YES\n";
                cout<<temp<<endl;
                for(int j=0;j<n;j++)
                {
                     m[a[j]]=0;
                }
                for(int j=0;j<n;j++)
                {
                     m[a[j]]++;
                }
                int j=n-1;
                x=temp;
                int count=0;
                while(1)
                {
                    while(!m[a[j]])
                    {
                        j--;
                    }
                    m[a[j]]--;
                   
                    if(m[x-a[j]])
                    {
                        cout<<a[j]<<" "<<x-a[j]<<endl;
                        m[x-a[j]]--;
                        x=a[j];
                        j--;
                        count+=2;
                    }
                    else
                    {
                        break;
                    }
                    
                
                 if(count==n)
                    break;   
                 }
                 break;
            }
            
        
        }
        if(!f)
        cout<<"NO\n";
    }
}