shared by the nation at their sacrifice . 
(ROOT (S (VP (VBN shared) (PP (IN by) (NP (DT the) (NN nation))) (PP (IN at) (NP (PRP$ their) (NN sacrifice)))) (. .)))
(ROOT (S (VP (VBN ) (PP (IN ) (NP (DT ) (NN ))) (PP (IN ) (NP (PRP$ ) (NN )))) (. )))