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