( ( Mercury ( -LRB- ( Hydrargyrum -RRB- ) ) ) ( ( is ( ( the ( only metal ) ) ( which ( is ( liquid ( at ( room temperature ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Mercury)) (PRN (-LRB- -LRB-) (NP (NNP Hydrargyrum)) (-RRB- -RRB-))) (VP (VBZ is) (NP (NP (DT the) (JJ only) (NN metal)) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (ADJP (JJ liquid) (PP (IN at) (NP (NN room) (NN temperature))))))))) (. .)))
Mercury (Hydrargyrum) is the only metal which is liquid at room temperature.
(ROOT (S (NP (NNP Mercury)) (VP (VBZ is) (NP (NP (DT the) (CD one) (NN metal)) (SBAR (WHNP (WDT that)) (S (VP (VBZ melts) (PP (IN below) (NP (NN room) (NN temperature)))))))) (. .)))