it had to be she , they know he was Wiping .
(ROOT_0 (S_0 (ATS_3 (ATS_1 (ATS_2 (SBAR_0 (S_1 (NP_0 (PRP_1 it)) (VP_5 (VBD_2 had) (S_2 (VP_0 (TO_0 to) (VP_1 (VB_0 be) (NP_0 (PRP_1 she)))))))) (COMMA_0 ,)) (NP_0 (PRP_1 they))) (VP_3 (VBP_0 know) (SBAR_0 (S_1 (NP_0 (PRP_1 he)) (VP_5 (VBD_2 was) (S_2 (VP_0 (VBG_0 Wiping)))))))) (DOT_0 .)))