( We ( ( ( measure ( air pressure ) ) ( in ( ( millibars ( -LRB- ( mb -RRB- ) ) ) ( with ( a barometer ) ) ) ) ) . ) )
(ROOT (S (NP (PRP We)) (VP (VB measure) (NP (NN air) (NN pressure)) (PP (IN in) (NP (NP (NP (NNS millibars)) (PRN (-LRB- -LRB-) (NP (NN mb)) (-RRB- -RRB-))) (PP (IN with) (NP (DT a) (NN barometer)))))) (. .)))
We measure air pressure in millibars (mb) with a barometer.
(ROOT (S (NP (NNP Millibar)) (VP (VBZ is) (NP (NP (DT the) (NN unit)) (VP (VBN used) (S (VP (TO to) (VP (VB measure) (NP (NN air) (NN pressure)))))))) (. .)))