toss it at the screen in frustration 
(ROOT (S (VP (VB toss) (NP (PRP it)) (PP (IN at) (NP (DT the) (NN screen))) (PP (IN in) (NP (NN frustration))))))
(ROOT (S (VP (VB ) (NP (PRP )) (PP (IN ) (NP (DT ) (NN ))) (PP (IN ) (NP (NN ))))))