#include<iostream>
#include<set>
#include<vector>
#include<algorithm>
using namespace std;
int t,n;

vector<int> check(int n,vector<int> a,int x){
    multiset<int> s;
    for(auto e : a)
        s.insert(e);
    vector<int> res;
    
    for(int i=0;i<n;i++){
        auto r = s.end();
        r--;
        int y = x - *r;
        s.erase(r);
        auto l = s.find(y);
        if(l == s.end()) return {};
        res.push_back(y);
        res.push_back(x-y);
        x = max(x-y,y);
        s.erase(l);
    }
    return res;
}

int main(){
    cin>>t;
    while(t--){
        cin>>n;
        vector<int> a(2*n);
        for(int i=0;i<2*n;i++)
            cin>>a[i];
        sort(a.begin(),a.end());
        
        int flag=0;
        for(int i=0;i<2*n-1;i++){
            int x=a[i]+a[2*n-1];
            vector<int> res = check(n,a,x);
            if(res.size()){
                cout<<"YES\n";
                cout<<x<<‘\n‘;
                for(int j=0;j<n;j++){
                    cout<<res[2*j]<<" "<<res[2*j+1]<<‘\n‘;
                }
                flag=1;
                break;
            }
        }
        if(flag==0) cout<<"NO\n";
    }
    return 0;
}