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(ROOT_0 (S_0 (ATS_2 (ATS_0 (COMMA_0 ,) (PP_2 (IN_0 on) (SBAR_0 (WHADVP_0 (WRB_0 when)) (S_1 (NP_0 (NNP_0 Noah)) (VP_5 (VBD_1 was) (NP_3 (JJ_1 gravel) (NNS_0 knees))))))) (APOSTROPHE_0 <apostrophe><apostrophe>)) (APOSTROPHE_0 <apostrophe><apostrophe>)))