['they', 'occupy', 'EmptyParameter', 'alien', 'by']
['<PRP>', 'amuse-31.1', 'EmptyParameter', "Synset('entrant.n.03')", 'by']
As they are occupied by the two non-corporeal aliens.
as <PRP> are occupied by the <NUMBER>0 non-corporeal Synset('entrant.n.03').