The bridge would work for a very short time but the stream isn't a clear defense.
( ( ( ( ( The bridge ) ( would ( work ( for ( a ( ( very short ) time ) ) ) ) ) ) but ) ( ( the stream ) ( ( is n't ) ( a ( clear defense ) ) ) ) ) . )
(ROOT (S (S (NP (DT The) (NN bridge)) (VP (MD would) (VP (VB work) (PP (IN for) (NP (DT a) (ADJP (RB very) (JJ short)) (NN time)))))) (CC but) (S (NP (DT the) (NN stream)) (VP (VBZ is) (RB n't) (NP (DT a) (JJ clear) (NN defense)))) (. .)))
There were too many enemies to use the bridge for long.
( There ( ( ( were too ) ( many ( enemies ( to ( ( use ( the bridge ) ) ( for long ) ) ) ) ) ) . ) )
(ROOT (S (NP (EX There)) (VP (VBD were) (ADVP (RB too)) (NP (JJ many) (NNS enemies) (S (VP (TO to) (VP (VB use) (NP (DT the) (NN bridge)) (PP (IN for) (ADVP (RB long)))))))) (. .)))