The short fibers may be made of {TAIL ~ a single crystal} such as {HEAD ~ whisker} or of a polycrystal 
The short fibers may be made of { TAIL ~ a single crystal } such as { HEAD ~ whisker } or of a polycrystal
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH