['they', 'hide', 'EmptyParameter', 'tree', 'behind'] ['seeker', 'appear', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter']
['<PRP>', 'concealment-16-1', 'EmptyParameter', "Synset('tree.n.03')", 'behind'] ["Synset('weapon.n.01')", 'appear-48.1.1', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter']
The four of them hide behind trees as two Seekers appear.
the four of <PRP> hide behind Synset('tree.n.03') as <NUMBER>0 Synset('weapon.n.01') appear.