['they', 'realize', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter'] ['what', 'happen', 'EmptyParameter', 'they', 'to']
['<PRP>', 'comprehend-87.2', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter'] ['what', 'occur-48.3', 'EmptyParameter', '<PRP>', 'to']
They realize what happened to them obviously happened to the shuttle.
<PRP> realize what happened to <PRP> obviously happened to the Synset('winder.n.03').