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))) (. .)))
Many controllers work in the control centers.
( ( Many controllers ) ( ( work ( in ( the ( control centers ) ) ) ) . ) )
(ROOT (S (NP (JJ Many) (NNS controllers)) (VP (VBP work) (PP (IN in) (NP (DT the) (NN control) (NNS centers)))) (. .)))