this friend mumbled up of . <apostrophe><apostrophe>
(ROOT_0 (S_0 (ATS_2 (ATS_3 (NP_1 (DT_1 this) (NN_2 friend)) (VP_4 (ATVP_3 (VBD_2 mumbled) (PRT_0 (RP_0 up))) (PP_1 (IN_1 of)))) (DOT_0 .)) (APOSTROPHE_0 <apostrophe><apostrophe>)))