['they', 'find', 'room', 'EmptyParameter', 'EmptyParameter']
['<PRP>', 'declare-29.4', "Synset('social_group.n.01')", 'EmptyParameter', 'EmptyParameter']
Inside, they find a room filled with eggs -- a hatchery.
Inside, <PRP> find a Synset('social_group.n.01') filled with Synset('food.n.01') -- a Synset('geographical_area.n.01').