(S (S (PP (IN For) (BASENP (NN comparison))) (COMMA ,) (S (BASENP (DT the) (NNP Exxon) (NNP Valdez) (NN oil) (NN spill)) (VP (VBD released) (BASENP (QP (RB nearly) (NN 40,000)) (NNS tons))))) (PERIOD .))