['he', 'hear', 'EmptyParameter', 'hologram', 'about']
['<PRP>', 'discover-84', 'EmptyParameter', '<OBJECT>1', 'about']
He heard about the hologram of the Voyager crew, including his son.
<PRP> heard about the <OBJECT>1 of the <VESSEL>1 crew, including <PRP> Synset('son.n.02').