a thirteen-year-old 's book report 
(ROOT (NP (NP (DT a) (ADJP (NP (CD thirteen) (HYPH -) (NN year)) (HYPH -) (JJ old)) (POS 's)) (NN book) (NN report)))
(ROOT (NP (NP (DT ) (ADJP (NP (CD ) (HYPH ) (NN )) (HYPH ) (JJ )) (POS )) (NN ) (NN )))