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