#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <tuple>
using namespace std;

tuple<int,int> minMin(vector<tuple<int,int>> *vectorPtrs)
    {
    vector<tuple<int,int>>::iterator vecIter = vectorPtrs->begin();
    tuple<int,int> retVal = vectorPtrs->front();
    
    for (int j=0; j<vectorPtrs->size(); ++j)
    {
            
        tuple<int,int> currentTuple = *vecIter;
        //cerr << "X:" << get<0>(currentTuple) << " Y:" << get<1>(currentTuple) <<endl;
        if((get<0>(currentTuple) < get<0>(retVal)) && (get<1>(currentTuple) < get<1>(retVal)))
            {
            retVal = currentTuple;
        }
        
        vecIter++;
    }
    
    return retVal;
}

tuple<int,int> maxMax(vector<tuple<int,int>> *vectorPtrs)
    {
    vector<tuple<int,int>>::iterator vecIter = vectorPtrs->begin();
    tuple<int,int> retVal = vectorPtrs->front();
    
    for (int j=0; j<vectorPtrs->size(); ++j)
    {
            
        tuple<int,int> currentTuple = *vecIter;
        //cerr << "X:" << get<0>(currentTuple) << " Y:" << get<1>(currentTuple) <<endl;
        if((get<0>(currentTuple) > get<0>(retVal)) && (get<1>(currentTuple) > get<1>(retVal)))
            {
            retVal = currentTuple;
        }
        
        vecIter++;
    }
    
    return retVal;
}

tuple<int,int> minMax(vector<tuple<int,int>> *vectorPtrs)
    {
    vector<tuple<int,int>>::iterator vecIter = vectorPtrs->begin();
    tuple<int,int> retVal = vectorPtrs->front();
    
    for (int j=0; j<vectorPtrs->size(); ++j)
    {
            
        tuple<int,int> currentTuple = *vecIter;
        //cerr << "X:" << get<0>(currentTuple) << " Y:" << get<1>(currentTuple) <<endl;
        if((get<0>(currentTuple) < get<0>(retVal)) && (get<1>(currentTuple) > get<1>(retVal)))
            {
            retVal = currentTuple;
        }
        
        vecIter++;
    }
    
    return retVal;
}

tuple<int,int> maxMin(vector<tuple<int,int>> *vectorPtrs)
    {
    vector<tuple<int,int>>::iterator vecIter = vectorPtrs->begin();
    tuple<int,int> retVal = vectorPtrs->front();
    
    for (int j=0; j<vectorPtrs->size(); ++j)
    {
            
        tuple<int,int> currentTuple = *vecIter;
        //cerr << "X:" << get<0>(currentTuple) << " Y:" << get<1>(currentTuple) <<endl;
        if((get<0>(currentTuple) > get<0>(retVal)) && (get<1>(currentTuple) < get<1>(retVal)))
            {
            retVal = currentTuple;
        }
        
        vecIter++;
    }
    
    return retVal;
}

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int queryCount = 0;
    cin >> queryCount;
    
    for(int i=0; i<queryCount; ++i)
        {
        bool allGood = true;
        
        int pointCount = 0;
        cin >> pointCount;
        
        if(pointCount<2)
            {
            cout << "NO"  <<endl;
            continue;
        }
        /*
        int NOT_SET= 32000;
        tuple<int,int> minXY(NOT_SET,NOT_SET);
        tuple<int,int> minXmaxY (NOT_SET,NOT_SET);
        tuple<int,int> minYmaxX (NOT_SET,NOT_SET);
        tuple<int,int> maxXmaxY (NOT_SET,NOT_SET);
            */
        
        
        vector<tuple<int,int>> *vectorPoints = new vector<tuple<int,int>>();
        for (int j=0; j<pointCount; ++j)
            {
            int x,y;
            cin >> x;
            cin >> y;
            
            //tuple<int,int> *myTuple = new tuple<int,int>(x,y) ;
            tuple<int,int> myTuple(x,y);
                cerr << "X:" << get<0>(myTuple) << " Y:" << get<1>(myTuple) <<endl;
            vectorPoints->push_back(myTuple);
                        
        }
        
        /*
        vector<tuple<int,int>>::iterator vecIter = vectorPoints->begin();
        for (int j=0; j<pointCount; ++j)
            {
            
            tuple<int,int> curentTuple = *vecIter;
            
            if( curentTuple) 
            
                
                
            vecIter++;
        }*/
        
       // cerr << "size:" << vectorPoints->size() << endl;

        tuple<int,int> minXminY= minMin(vectorPoints);
        tuple<int,int> minXmaxY = minMax(vectorPoints);
        tuple<int,int> minYmaxX = maxMin(vectorPoints);
        tuple<int,int> maxXmaxY = maxMax(vectorPoints);
        
        // if duplicate, add a new point for the missing corner.
        
        vector<tuple<int,int>>::iterator vecIter = vectorPoints->begin();
        for (int j=0; j<pointCount; ++j)
            {
            
            tuple<int,int> currentTuple = *vecIter++;
            
            
            
            if(( get<0>(currentTuple) == get<0>(minXminY) ) || ( get<0>(currentTuple) == get<0>(maxXmaxY) ) )
                {
                //on the X lines. Let's make sure it's not outside.
                if((get<1>(currentTuple) >= get<1>(minXminY) ) || ( get<1>(currentTuple) <= get<1>(maxXmaxY) ))
                {   
                    cerr << "On X axis ";
                    cerr << "X:" << get<0>(currentTuple) << " Y:" << get<1>(currentTuple) <<endl;
                    continue;}
            }
            else if((get<1>(currentTuple) == get<1>(minXminY) ) || ( get<1>(currentTuple) == get<1>(maxXmaxY) ) )
                {
                //on the Y lines. Let's make sure it's not outside.
                cerr << "On Y axis ";
                cerr << "X:" << get<0>(currentTuple) << " Y:" << get<1>(currentTuple) <<endl;
                if((get<0>(currentTuple) >= get<0>(minXminY) ) || ( get<0>(currentTuple) <= get<0>(maxXmaxY) ))
                {continue;}   
            }
            else{
                cerr << "not found!!";
                cerr << "X:" << get<0>(currentTuple) << " Y:" << get<1>(currentTuple) <<endl;
                allGood = false;
                break;
            }
        }
        
        
        
        
        /*
        tuple<int,int> currentTuple = maxMax(vectorPoints);
        cout << "HELO" <<endl;
        cout << "X:" << get<0>(currentTuple) << " Y:" << get<1>(currentTuple) <<endl;
          */  

        if (allGood)
            cout << "YES"  <<endl;
        else
            cout << "NO"  <<endl;
    }
    
    
    return 0;
}