distinguish one sci-fi work from another 
(ROOT (S (VP (VB distinguish) (NP (CD one) (NML (NN sci-) (NN fi)) (NN work)) (PP (IN from) (NP (DT another))))))
(ROOT (S (VP (VB ) (NP (CD ) (NML (NN ) (NN )) (NN )) (PP (IN ) (NP (DT ))))))