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