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)))) (. .)))
The bridge would work temporarily.
( ( The bridge ) ( ( would ( work temporarily ) ) . ) )
(ROOT (S (NP (DT The) (NN bridge)) (VP (MD would) (VP (VB work) (ADVP (RB temporarily)))) (. .)))