( Conductors ( ( ( allow ( ( the ( free flow ) ) ( of electrons ) ) ) ( through them ) ) . ) )
(ROOT (S (NP (NNS Conductors)) (VP (VBP allow) (NP (NP (DT the) (JJ free) (NN flow)) (PP (IN of) (NP (NNS electrons)))) (PP (IN through) (NP (PRP them)))) (. .)))
Conductors allow the free flow of electrons through them.
(ROOT (S (NP (DT A) (NN conductor)) (VP (VBZ allows) (S (NP (NNS electrons)) (VP (TO to) (VP (VB move) (PP (IN in) (NP (DT an) (JJ electrochemical) (NN system)))))))))