{HEAD ~ A collapsible trailer} to be towed by a bicycle has {TAIL ~ front and rear U shaped members} pivotally mounted on an axle to the ends of which wheels can be attached 
has
{ HEAD ~ A collapsible trailer } to be towed by a bicycle has { TAIL ~ front and rear U shaped members } pivotally mounted on an axle to the ends of which wheels can be attached
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH