It comprises {HEAD ~ a cylinder} , which is closed at {TAIL ~ one end}, and piston , which slides inside the cylinder  
It comprises { HEAD ~ a cylinder } , which is closed at { TAIL ~ one end } , and piston , which slides inside the cylinder
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH