legs queasy was why back stones out out .
(ROOT_0 (S_0 (ATS_3 (ATS_1 (NP_1 (NNS_0 legs)) (ADVP_0 (RB_0 queasy))) (VP_3 (VBD_1 was) (VP_2 (ATVP_2 (VBN_0 why) (ADVP_0 (RB_1 back) (NP_4 (NNS_1 stones)))) (ADVP_0 (RB_1 out) (RB_1 out))))) (DOT_0 .)))