It was later <apostrophe>s a single navy who to be heard .
(ROOT_0 (S_0 (ATS_3 (NP_1 (PRP_0 It)) (VP_4 (ATVP_1 (VBD_1 was) (RB_1 later)) (VP_5 (VBZ_0 <apostrophe>s) (NP_2 (NP_6 (ATNP_1 (DT_0 a) (JJ_1 single)) (NN_1 navy)) (SBAR_0 (WHNP_0 (WP_0 who)) (S_2 (VP_0 (TO_0 to) (VP_1 (VB_0 be) (VP_2 (VBN_0 heard)))))))))) (DOT_0 .)))