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