is one that should be thrown back in the river 
(ROOT (VP (VBZ is) (NP (NP (CD one)) (SBAR (WHNP (WDT that)) (S (VP (MD should) (VP (VB be) (VP (VBN thrown) (ADVP (RB back)) (PP (IN in) (NP (DT the) (NN river)))))))))))
(ROOT (VP (VBZ ) (NP (NP (CD )) (SBAR (WHNP (WDT )) (S (VP (MD ) (VP (VB ) (VP (VBN ) (ADVP (RB )) (PP (IN ) (NP (DT ) (NN )))))))))))