Many controllers work at the FAA's 22 Air Route Traffic Control Centers.
( ( ( Many ( controllers work ) ) ( at ( the FAA ) ) ) ( ( 's ( 22 ( Air ( Route ( Traffic ( Control Centers ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (JJ Many) (NNS controllers) (NN work)) (PP (IN at) (NP (DT the) (NNP FAA)))) (VP (VBZ 's) (NP (CD 22) (NNP Air) (NNP Route) (NNP Traffic) (NNP Control) (NNPS Centers))) (. .)))
Just one controller is in each center.
( ( Just ( one controller ) ) ( ( is ( in ( each center ) ) ) . ) )
(ROOT (S (NP (RB Just) (CD one) (NN controller)) (VP (VBZ is) (PP (IN in) (NP (DT each) (NN center)))) (. .)))