( ( Their work ) ( ( focuses ( on ( determining ( which ( ( parts ( of ( the brain ) ) ) ( control ( which functions ) ) ) ) ) ) ) ; ) )
(ROOT (S (NP (PRP$ Their) (NN work)) (VP (VBZ focuses) (PP (IN on) (S (VP (VBG determining) (SBAR (WHNP (WDT which)) (S (NP (NP (NNS parts)) (PP (IN of) (NP (DT the) (NN brain)))) (VP (VBP control) (SBAR (WHNP (WDT which)) (S (VP (VBZ functions))))))))))) (: ;)))
Their work focuses on determining which parts of the brain control which functions;
(ROOT (S (ADVP (RB Not) (RB surprisingly)) (, ,) (NP (JJ controlling) (NN flight)) (VP (VBZ is) (NP (NP (DT the) (NN function)) (PP (IN of) (NP (NP (DT the) (ADJP (RBS most) (JJ developed)) (NN part)) (PP (IN of) (NP (NP (DT a) (NN bird) (POS 's)) (NN brain))))))) (. .)))