one well-timed explosion in a movie can be a knockout , 
(ROOT (S (NP (NP (CD one) (ADJP (RB well) (HYPH -) (VBN timed)) (NN explosion)) (PP (IN in) (NP (DT a) (NN movie)))) (VP (MD can) (VP (VB be) (NP (DT a) (NN knockout)))) (, ,)))
(ROOT (S (NP (NP (CD ) (ADJP (RB ) (HYPH ) (VBN )) (NN )) (PP (IN ) (NP (DT ) (NN )))) (VP (MD ) (VP (VB ) (NP (DT ) (NN )))) (, )))