( However ( , ( diet ( ( ( can still ) ( play ( ( an ( important role ) ) ( in ( controlling ( allergic reactions ) ) ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB However)) (, ,) (NP (NN diet)) (VP (MD can) (ADVP (RB still)) (VP (VB play) (NP (NP (DT an) (JJ important) (NN role)) (PP (IN in) (NP (VBG controlling) (JJ allergic) (NNS reactions)))))) (. .)))
However, diet can still play an important role in controlling allergic reactions.
(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))))))) (. .)))