an expiration date passed a long time ago 
(ROOT (S (NP (DT an) (NN expiration) (NN date)) (VP (VBD passed) (PP (NP (DT a) (JJ long) (NN time)) (RB ago)))))
(ROOT (S (NP (DT ) (NN ) (NN )) (VP (VBD ) (PP (NP (DT ) (JJ ) (NN )) (RB )))))