( ( torr ( ( A unit ) ( of ( measure ( of pressure ) ) ) ) ) ( , ( ( 760 Torr ) ( ( is ( ( ( standard pressure ) ( at ( ( sea ( level ( transmission microscope ) ) ) ( ( ( A microscope ) ( in which ) ) ( ( the ( image-forming rays ) ) ( pass ( ( through ( -LRB- ( ( are ( transmitted by ) ) -RRB- ) ) ) ( the specimen ) ) ) ) ) ) ) ) ( being observed ) ) ) . ) ) ) )
(ROOT (S (S (VP (VB torr) (NP (NP (DT A) (NN unit)) (PP (IN of) (NP (NP (NN measure)) (PP (IN of) (NP (NN pressure)))))))) (, ,) (NP (NNP 760) (NNP Torr)) (VP (VBZ is) (NP (NP (JJ standard) (NN pressure)) (PP (IN at) (NP (NP (NN sea) (NN level) (NN transmission) (NN microscope)) (SBAR (WHNP (NP (DT A) (NN microscope)) (WHPP (IN in) (WHNP (WDT which)))) (S (NP (DT the) (JJ image-forming) (NNS rays)) (VP (VBP pass) (PP (IN through) (PRN (-LRB- -LRB-) (S (VP (VBP are) (VP (VBN transmitted) (PP (IN by))))) (-RRB- -RRB-)) (NP (DT the) (NN specimen)))))))) (VP (VBG being) (VP (VBN observed))))) (. .)))
torr A unit of measure of pressure, 760 Torr is standard pressure at sea level transmission microscope A microscope in which the image-forming rays pass through (are transmitted by) the specimen being observed.
(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.