Plus The mounds let because they sounded to let , at the story .
(ROOT_0 (S_0 (ATS_3 (ATS_1 (CC_0 Plus) (NP_1 (DT_1 The) (NNS_0 mounds))) (VP_3 (VBD_0 let) (SBAR_0 (IN_2 because) (S_1 (NP_0 (PRP_1 they)) (VP_5 (ATVP_3 (ATVP_2 (VBD_1 sounded) (S_2 (VP_0 (TO_0 to) (VP_1 (VB_0 let))))) (COMMA_0 ,)) (PP_0 (IN_1 at) (NP_5 (DT_0 the) (NN_2 story)))))))) (DOT_0 .)))