like a soft drink that 's been sitting open too long : 
(ROOT (PP (IN like) (NP (NP (DT a) (JJ soft) (NN drink)) (SBAR (WHNP (WDT that)) (S (VP (VBZ 's) (VP (VBN been) (VP (VBG sitting) (ADJP (JJ open)) (ADVP (RB too) (RB long)))))))) (: :)))
(ROOT (PP (IN ) (NP (NP (DT ) (JJ ) (NN )) (SBAR (WHNP (WDT )) (S (VP (VBZ ) (VP (VBN ) (VP (VBG ) (ADJP (JJ )) (ADVP (RB ) (RB )))))))) (: )))