Using the manipulating handle {HEAD ~ the display unit} is wheeled to {TAIL ~ the site} of the demonstration 
is wheeled to
Using the manipulating handle { HEAD ~ the display unit } is wheeled to { TAIL ~ the site } of the demonstration
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH