They mutter Within the boulders do slid back with the highlights .
(ROOT_0 (S_0 (ATS_3 (NP_1 (PRP_0 They)) (VP_4 (ATVP_1 (VBP_0 mutter) (PP_2 (IN_0 Within) (NP_6 (DT_0 the) (NNS_1 boulders)))) (VP_1 (VB_0 do) (S_2 (VP_0 (ATVP_4 (VBD_0 slid) (RB_1 back)) (PP_2 (IN_0 with) (NP_6 (DT_0 the) (NNS_1 highlights)))))))) (DOT_0 .)))