who ca n't quite distinguish one sci-fi work from another 
(ROOT (SBAR (WHNP (WP who)) (S (VP (MD ca) (RB n't) (ADVP (RB quite)) (VP (VB distinguish) (NP (CD one) (NML (NN sci-) (NN fi)) (NN work)) (PP (IN from) (NP (DT another))))))))
(ROOT (SBAR (WHNP (WP )) (S (VP (MD ) (RB ) (ADVP (RB )) (VP (VB ) (NP (CD ) (NML (NN ) (NN )) (NN )) (PP (IN ) (NP (DT ))))))))