In preferred embodiments, {TAIL ~ the pitch} between {HEAD ~ corrugations} may be five inches, with a depth of one half inch 
In preferred embodiments , { TAIL ~ the pitch } between { HEAD ~ corrugations } may be five inches , with a depth of one half inch
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH