{TAIL ~ The percentage} of {HEAD ~ crossover points} of the exposed sacrificial fiber channels is preferably 25 to 75%, most preferably 30 to 50% 
{ TAIL ~ The percentage } of { HEAD ~ crossover points } of the exposed sacrificial fiber channels is preferably 25 to 75 % , most preferably 30 to 50 %
TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH