(S (S (BASENP (NNP United) (NNP Air) (NNPS Lines) (NN spokesman) (NNP Jeff) (NNP Green)) (VP (VBD said) (SBAR (S (BASENP (DT a) (NN flight) (NN attendant)) (VP (VBD was) (VP (VP (VBN alerted) (PP (IN by) (BASENP (DT a) (NN passenger)))) (PP (TO to) (NP (BASENP (DT another) (NN passenger) (POS 's)) (BASENP (JJ suspicious) (NNS materials) (CC and) (NNS wires)))))))))) (PERIOD .))