They keep out , to try plastic .
(ROOT_0 (S_0 (ATS_3 (NP_1 (PRP_0 They)) (VP_4 (ATVP_3 (ATVP_2 (VB_0 keep) (PRT_0 (RP_0 out))) (COMMA_0 ,)) (S_2 (VP_0 (TO_0 to) (VP_1 (VB_0 try) (ADJP_0 (JJ_0 plastic))))))) (DOT_0 .)))