( ( ( ( Air pollution ) and ) ( acid rain ) ) ( ( have ( ( ( caused damage ) ( to ( ( marble and ) stonework ) ) ) ( at ( the Parthenon ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Air) (NN pollution)) (CC and) (NP (JJ acid) (NN rain))) (VP (VBP have) (VP (VBN caused) (NP (NN damage)) (PP (TO to) (NP (NN marble) (CC and) (NN stonework))) (PP (IN at) (NP (DT the) (NNP Parthenon))))) (. .)))
Air pollution and acid rain have caused damage to marble and stonework at the Parthenon.
(ROOT (S (NP (JJ Acid) (NN rain)) (VP (MD may) (VP (VB be) (VP (VBN caused) (PP (IN by) (NP (NN air) (NN pollution)))))) (. .)))