The body has a recessed portion and a plurality of protrusion portions disposed beside the recessed portion, wherein {HEAD ~ the protrusion portions} protrude from {TAIL ~ the recessed portion} 
protrude from
The body has a recessed portion and a plurality of protrusion portions disposed beside the recessed portion , wherein { HEAD ~ the protrusion portions } protrude from { TAIL ~ the recessed portion }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL