Here, {HEAD ~ the honeycomb units} of {TAIL ~ the ceramic block} may have three kinds of shapes 
of
Here , { HEAD ~ the honeycomb units } of { TAIL ~ the ceramic block } may have three kinds of shapes
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH