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