n=int(raw_input())
l=[]
flag=1
for i in range(n):
    n_sides=int(raw_input())
    for j in range(n_sides):
        temp=(raw_input().split(' '))
        if not('0' in temp):
            flag=0
            
    if flag==0:
        print "NO"
    else:
        print "YES"
    flag=1    
    #x=[(l[i][0]) for i in range(n_sides)]
    #y=[(l[i][1]) for i in range(n_sides)]
    #print max(x),max(y)
        
    
    l=[]