(S (S (NP (NP (BASENP (DT Some)) (PP (IN of) (NP (BASENP (DT the) (NNS cracks)) (PP (IN on) (BASENP (NN ocean) (NNS floors)))))) (PRN (COMMA ,) (SBAR (WHADVP (WRB where)) (S (BASENP (NN oil)) (VP (VBZ has) (VP (VBN leaked) (PP (IN from)))))) (COMMA ,))) (VP (VBP have) (VP (VBN occurred) (ADVP (RB naturally))))) (PERIOD .))