that the film opens with maggots crawling on a dead dog 
(ROOT (SBAR (IN that) (S (NP (DT the) (NN film)) (VP (VBZ opens) (PP (IN with) (S (NP (NNS maggots)) (VP (VBG crawling) (PP (IN on) (NP (DT a) (JJ dead) (NN dog))))))))))
(ROOT (SBAR (IN ) (S (NP (DT ) (NN )) (VP (VBZ ) (PP (IN ) (S (NP (NNS )) (VP (VBG ) (PP (IN ) (NP (DT ) (JJ ) (NN ))))))))))