( Mercury ( ( is ( ( the ( only metal ) ) ( that ( exists ( as ( ( a liquid ) ( at ( room temperature ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Mercury)) (VP (VBZ is) (NP (NP (DT the) (JJ only) (NN metal)) (SBAR (WHNP (WDT that)) (S (VP (VBZ exists) (PP (IN as) (NP (NP (DT a) (NN liquid)) (PP (IN at) (NP (NN room) (NN temperature)))))))))) (. .)))
Mercury is the only metal that exists as a liquid at room temperature.
(ROOT (S (NP (NNP Mercury)) (VP (VBZ is) (RB not) (NP (DT a) (JJ solid) (ADJP (RB even) (PP (IN at) (NP (NN room)))) (NN temperature))) (. .)))