By gravel been are n<apostrophe>t a green ?
(ROOT_0 (S_0 (ATS_3 (NP_1 (IN_2 By) (NN_3 gravel)) (VP_4 (VBN_0 been) (S_2 (VP_0 (ATVP_1 (VBP_0 are) (RB_1 n<apostrophe>t)) (NP_5 (DT_0 a) (JJ_0 green)))))) (DOT_0 ?)))