小白求解，下面这段代码哪里有问题

import math
while True:
a, b ,c = eval(raw_input("Enter three cofficients"))
if a==0:
print "fault"
else:
delta = b * b - 4 * a * c
if delta <0:
print "without real roots"
elif delta ==0:
print "only one roots ", (-b/2.0/a)
else delta >0:
fdiscRoot = math.sqrt(delta)
fr1 = (-b + fdiscRoot) / (2*a)
fr1 = (-b - fdiscRoot) / (2*a)
print "two roots are: ", fr1 ,fr2
ch=raw_input("please input")
if ch!='c' and ch!='C':
break