Consequently, it is difficult to sever {TAIL ~ a thin parallel sided strip} of {HEAD ~ foam sheet} so that its edge structure can be examined microscopically 
Consequently , it is difficult to sever { TAIL ~ a thin parallel sided strip } of { HEAD ~ foam sheet } so that its edge structure can be examined microscopically
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH