who sleeping in mounds because air was ballet be over huge feathers .
(ROOT_0 (S_0 (ATS_3 (ATS_1 (ATS_2 (SBAR_0 (WHNP_0 (WP_0 who)) (S_2 (VP_0 (VBG_0 sleeping) (PP_2 (IN_0 in) (NP_3 (NNS_1 mounds)))))) (ADVP_0 (IN_2 because))) (NP_0 (NN_2 air))) (VP_3 (VBD_1 was) (ADJP_0 (JJ_0 ballet) (S_2 (VP_0 (ATVP_0 (VB_0 be) (PRT_0 (RP_0 over))) (NP_2 (JJ_1 huge) (NNS_1 feathers))))))) (DOT_0 .)))