#include<iostream>
using namespace std;
int n;
int main(){
	cin>>n;
	for(int i=0;i<n;i++){
		double x[4],y[4];
		char a;
		for(int i=0;i<4;i++){
			cin>>x[i]>>a>>y[i];
		}
		if((x[0]-x[1])/(y[0]-y[1])==(x[2]-x[3])/(y[2]-y[3])){
			cout<<"YES"<<endl;
		}
		else{
			cout<<"NO"<<endl;
		}
	}
	return 0;
}
