( ( Air Pressure ) ( ( -LRB- ( ( atmospheric pressure ) -RRB- ) ) ( ( air pressure ) ( ( is ( ( the force ) ( ( exerted ( on ( a surface ) ) ) ( by ( ( the weight ) ( of ( ( the air ) ( above it ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (NP (NNP Air) (NNP Pressure)) (PRN (-LRB- -LRB-) (NP (JJ atmospheric) (NN pressure)) (-RRB- -RRB-)) (NP (NN air) (NN pressure)) (VP (VBZ is) (NP (NP (DT the) (NN force)) (VP (VBN exerted) (PP (IN on) (NP (DT a) (NN surface))) (PP (IN by) (NP (NP (DT the) (NN weight)) (PP (IN of) (NP (NP (DT the) (NN air)) (PP (IN above) (NP (PRP it)))))))))) (. .)))
Air Pressure (atmospheric pressure) air pressure is the force exerted on a surface by the weight of the air above it.
(ROOT (S (PP (IN At) (NP (NP (DT the) (NN earth) (POS 's)) (NN surface))) (, ,) (NP (NP (DT the) (NN air) (NN pressure)) (VP (VBN exerted) (PP (IN on) (NP (PRP you))))) (VP (VBZ is) (NP (NP (DT a) (NN result)) (PP (IN of) (NP (NP (DT the) (NN weight)) (PP (IN of) (NP (NP (NN air)) (PP (IN above) (NP (PRP you))))))))) (. .)))