#include<cstdio>

#include<cstring>

#include<cmath>

#include<iostream>

#include<algorithm>

#include<queue>

using namespace std;

const int maxn = ;

const int maxe = ;

const int INF = 0x3f3f3f;

const double eps = 1e-;

const double PI = acos(-1.0);

struct Point{

    double x,y;

    Point(double x=, double y=) : x(x),y(y){ }    //构造函数

};

typedef Point Vector;

Vector operator + (Vector A , Vector B){return Vector(A.x+B.x,A.y+B.y);}

Vector operator - (Vector A , Vector B){return Vector(A.x-B.x,A.y-B.y);}

Vector operator * (Vector A , double p){return Vector(A.x*p,A.y*p);}

Vector operator / (Vector A , double p){return Vector(A.x/p,A.y/p);}

bool operator < (const Point& a,const Point& b){

    return a.x < b.x ||( a.x == b.x && a.y < b.y);

}

int dcmp(double x){

    if(fabs(x) < eps) return ;

    else              return x <  ? - : ;

}

bool operator == (const Point& a, const Point& b){

    return dcmp(a.x - b.x) ==  && dcmp(a.y - b.y) == ;

}

double Dot(Vector A, Vector B){ return A.x*B.x + A.y*B.y; }

double Cross(Vector A, Vector B)  { return A.x*B.y - A.y * B.x; }

double Length(Vector A)    { return sqrt(Dot(A,A)); }

bool SegmentLineIntersection(Point a1,Point a2,Point b1,Point b2){  //a1a2是直线，b1b2是线段；

    double c1 = Cross(a2-a1,b1-a1), c2 = Cross(a2-a1,b2-a1);

    return dcmp(c1) * dcmp(c2) <  || dcmp(c1) ==  || dcmp(c2) == ;

}

Point read_point(){

    Point A;

    scanf("%lf %lf",&A.x,&A.y);

    return A;

}

/******************************分割线*******************************/

Point P[maxn][];

int n;

int main()

{

   //freopen("E:\\acm\\input.txt","r",stdin);

    int T;

    cin>>T;

    while(T--){

        cin>>n;

        for(int i=;i<=n;i++){

            P[i][] = read_point();

            P[i][] = read_point();

        }

        bool ans = false;

        for(int i=;i<n;i++)

          for(int k=;k<=;k++)

            for(int j=i+;j<=n;j++)

               for(int m=;m<=;m++){  //确定两个端点P[i][k]和P[j][m];接下来判断过这两点直线是否穿过所有线段；

                  if(P[i][k] == P[j][m])  continue;

                  int s;

                  for(s=;s<=n;s++){

                      if(!SegmentLineIntersection(P[i][k],P[j][m],P[s][],P[s][])) break;

                  }

                  if(s == n+) { ans = true;  goto print; }

            }

        print:

        if(ans || n==)  printf("Yes!\n");  //n == 1没考虑，WA了两次看discuss别人说的；

        else     printf("No!\n");

    }

}