them discovered down but knew back by Noah on freezing .
(ROOT_0 (S_0 (ATS_3 (NP_1 (PRP_0 them)) (VP_4 (ATVP_1 (VP_5 (VBD_0 discovered) (ADJP_0 (RP_0 down))) (CC_0 but)) (VP_5 (ATVP_3 (ATVP_4 (VBD_0 knew) (RB_1 back)) (PP_1 (IN_1 by) (NP_0 (NNP_0 Noah)))) (PP_0 (IN_1 on) (NP_2 (NN_3 freezing)))))) (DOT_0 .)))