( ( ( Another ( common unit ) ) ( of pressure ) ) ( ( is ( ( the ( torr ( , ( or millimeter ) ) ) ) ( of mercury ) ) ) . ) )
(ROOT (S (NP (NP (DT Another) (JJ common) (NN unit)) (PP (IN of) (NP (NN pressure)))) (VP (VBZ is) (NP (NP (DT the) (NN torr) (, ,) (CC or) (NN millimeter)) (PP (IN of) (NP (NN mercury))))) (. .)))
Another common unit of pressure is the torr, or millimeter of mercury.
(ROOT (S (NP (DT A) (NN torr)) (VP (VBZ is) (NP (NP (DT a) (NN unit)) (VP (VBN used) (S (VP (TO to) (VP (VB measure) (NP (NN pressure)))))))) (. .)))
A torr is a unit used to measure pressure.