One end of the tube 45 is in communication with one end of the tube 46, the other end of the tube 46 is in communication with one end of the tube 48, and {HEAD ~ the other end} of {TAIL ~ the tube} 48 is in communication with one end of the tube 50 
of
One end of the tube 45 is in communication with one end of the tube 46 , the other end of the tube 46 is in communication with one end of the tube 48 , and { HEAD ~ the other end } of { TAIL ~ the tube } 48 is in communication with one end of the tube 50
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH 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 TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH