import java.io.*;
import java.util.*;
/**
 *
 * @author Sourav Kumar Paul
 */
  class SolveB {
    public static void main(String[] args) throws IOException{
        Reader in = new Reader(new InputStreamReader(System.in));
        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
       int q = in.nextInt();
       while(q-->0)
       {
           int n = in.nextInt();
           int x[] = new int[n];
           int y[] = new int[n];
           int minx = Integer.MAX_VALUE;
           int miny = minx;
           int maxx = Integer.MIN_VALUE;
           int maxy = maxx;
           for(int i=0; i<n; i++)
           {
               x[i] = in.nextInt();
               y[i] = in.nextInt();
               minx = Math.min(minx,x[i]);
               maxx = Math.max(maxx, x[i]);
               miny = Math.min(miny, y[i]);
               maxy = Math.max(maxy, y[i]);
           }
           boolean fa= false;
           for(int i=0; i<n; i++)
           {
               if((x[i] == minx) || (x[i] == maxx))
               {
                   if(y[i]>=miny && y[i] <=maxy)
                       ;
                   else
                   {
                       out.println(x[i]+" "+y[i]);
                       fa = true;
                   }
               }
               else if((y[i] == miny) || (y[i] == maxy))
               {
                   if(x[i]>=minx && x[i] <=maxx)
                       ;
                   else
                   {
                       
                       //out.println(x[i]+" "+y[i]);
                       fa = true;
                   }
               }
               else
               {
                   
                       //out.println(x[i]+" "+y[i]);
                   fa = true;
               }
           }
           if(!fa)
               out.println("YES");
           else
               out.println("NO");
       }
        out.flush();
        out.close();
    }
    public static class Reader {
        public BufferedReader reader;
        public StringTokenizer st;

        public Reader(InputStreamReader stream) {
            reader = new BufferedReader(stream);
            st = null;
        }

        public String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return st.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public String nextLine() throws IOException{
            return reader.readLine();
        }
        public long nextLong(){
            return Long.parseLong(next());
        }
        public double nextDouble(){
            return Double.parseDouble(next());
        }

    }
}