sentence: Cars emit large amounts of carbon dioxide , so that is the cause of the grey skies of some cities like Madrid , Beijing and New York and this has to change .
modified: The cars pollute big amounts of carbon dioxide , so that is the result of the grey skies of some cities like Madrid Beijing or New York are grey and this has to change .
transformation: DET, VERB, ADJ, NOUN, PUNCT, CONJ, OTHER