crocodile hunter steve irwin do what he does best 
(ROOT (S (NP (NML (NN crocodile) (NN hunter)) (NNP steve) (NNP irwin)) (VP (VB do) (SBAR (WHNP (WP what)) (S (NP (PRP he)) (VP (VBZ does) (ADVP (JJS best))))))))
(ROOT (S (NP (NML (NN ) (NN )) (NNP ) (NNP )) (VP (VB ) (SBAR (WHNP (WP )) (S (NP (PRP )) (VP (VBZ ) (ADVP (JJS ))))))))