Accordingly, the outer passage 11 has an annular cross section, whereas {HEAD ~ the inner passage} 10 has {TAIL ~ a full cross section} 
has
Accordingly , the outer passage 11 has an annular cross section , whereas { HEAD ~ the inner passage } 10 has { TAIL ~ a full cross section }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL