They did because it was not know off a snow drink , the mounds .
(ROOT_0 (S_0 (ATS_3 (NP_1 (PRP_0 They)) (VP_4 (VBD_0 did) (SBAR_0 (IN_2 because) (S_1 (NP_0 (PRP_1 it)) (VP_5 (ATVP_1 (VBD_1 was) (RB_1 not)) (VP_1 (ATVP_0 (VB_0 know) (PRT_0 (RP_0 off))) (NP_3 (ATNP_0 (NP_6 (ATNP_1 (DT_0 a) (NN_3 snow)) (NN_1 drink)) (COMMA_0 ,)) (NP_6 (DT_0 the) (NNS_1 mounds))))))))) (DOT_0 .)))