['they', 'arrive', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter']
['<PRP>', 'escape-51.1', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter']
The habitat is self-contained, built from the parts of ships they arrived.
the Synset('geographical_area.n.01') is self-contained, built from the Synset('idea.n.01') of Synset('craft.n.02') <PRP> arrived.