( ( The result ) ( ( was ( ( the ( world 's ) ) ( first ( controlled ( nuclear ( chain reaction ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN result)) (VP (VBD was) (NP (NP (DT the) (NN world) (POS 's)) (JJ first) (ADJP (JJ controlled)) (JJ nuclear) (NN chain) (NN reaction))) (. .)))
The result was the world's first controlled nuclear chain reaction.
(ROOT (S (NP (NNP Control) (NNS rods)) (VP (VBP play) (NP (NP (DT an) (JJ important) (NN role)) (PP (IN in) (NP (NP (DT the) (NN modulation)) (PP (IN of) (NP (DT the) (JJ nuclear) (NN chain) (NN reaction))))))) (. .)))