( ( A millibar ) ( ( is ( ( a unit ) ( that ( is ( used ( to ( report ( the ( the ( atmospheric pressure ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (NN millibar)) (VP (VBZ is) (NP (NP (DT a) (NN unit)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB report) (NP (DT the) (DT the) (JJ atmospheric) (NN pressure))))))))))) (. .)))
A millibar is a unit that is used to report the the atmospheric pressure.
(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)))))))) (. .)))