{HEAD ~ Projectors} are arranged on, in, or about {TAIL ~ the structure} to project light toward the object 
are arranged on
{ HEAD ~ Projectors } are arranged on , in , or about { TAIL ~ the structure } to project light toward the object
HEAD HEAD HEAD HEAD HEAD REL REL REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH