( Metal ( ( ( ( retains ( this heat ) ) and ) ( increases ( ( the chances ) ( of ( permanent stains ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Metal)) (VP (VP (VBZ retains) (NP (DT this) (NN heat))) (CC and) (VP (VBZ increases) (NP (NP (DT the) (NNS chances)) (PP (IN of) (NP (JJ permanent) (NNS stains)))))) (. .)))
Metal retains this heat and increases the chances of permanent stains.
(ROOT (S (NP (NP (DT A) (-LRB- -LRB-) (NN n) (-RRB- -RRB-) (NN increase)) (PP (IN in) (NP (NN length)))) (VP (VBZ happens) (PP (TO to) (NP (NN metal) (NN railroad) (NNS tracks))) (PP (IN during) (NP (NP (DT the) (NN heat)) (PP (IN of) (NP (DT a) (NN summer) (NN day)))))) (. .)))