(S (S (S (BASENP (NNP Preston)) (VP (ADVP (RB however)) (VP (VBD was) (VP (VP (VBN greeted) (PP (IN with) (BASENP (JJ good) (NN news)))) (PP (IN at) (BASENP (DT the) (NN post) (NN office))))))) (SBAR (WHADVP (WRB when)) (S (BASENP (PRP he)) (VP (VP (VBD opened) (BASENP (DT the) (NN letter))) (CC and) (VP (VBD discovered) (SBAR (IN that) (S (BASENP (PRPD his) (NN matter)) (VP (VBD had) (VP (VBN been) (VP (VBN dropped))))))))))) (PERIOD .))