They always used snow to fleas .
(ROOT_0 (S_0 (ATS_3 (ATS_1 (NP_1 (PRP_0 They)) (ADVP_0 (RB_0 always))) (VP_3 (ATVP_3 (VBD_2 used) (NP_2 (NN_3 snow))) (PP_2 (TO_0 to) (NP_3 (NNS_1 fleas))))) (DOT_0 .)))