Preferably a selected object will be highlighted in some way, for example by {TAIL ~ a change} in color or variation in the degree of {HEAD ~ luminosity} on the screen to confirm the operators selection 
Preferably a selected object will be highlighted in some way , for example by { TAIL ~ a change } in color or variation in the degree of { HEAD ~ luminosity } on the screen to confirm the operators selection
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH