Thus it becomes imperative that the foam sheet samples be severed by {HEAD ~ means} of {TAIL ~ a thin cutting blade} such as a razor blade 
of
Thus it becomes imperative that the foam sheet samples be severed by { HEAD ~ means } of { TAIL ~ a thin cutting blade } such as a razor blade
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH