(S (S (BASENP (JJ Last) (NN year)) (COMMA ,) (S (S (BASENP (PRPD her) (NN brother) (NNP Zac)) (VP (VBD had) (VP (VBN completed) (BASENP (DT a) (NN circumnavigation))))) (SBAR (WHADVP (WRB when)) (S (BASENP (PRP he)) (VP (VP (VP (VBD sailed) (ADVP (RB solo))) (PP (IN around) (BASENP (DT the) (NN world)))) (PP (IN at) (NP (BASENP (DT the) (NN age)) (PP (IN of) (BASENP (NN seventeen)))))))))) (PERIOD .))