['they', 'move', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter']
['<PRP>', 'act-114-1-1', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter']
They are undetected by the various drones while they move down a corridor.
<PRP> are Synset('undetected.a.01') by the various Synset('wind_instrument.n.01') while <PRP> move down a <ORGANIZATION>4.