( ( The ( Kelvin ( and ( Rankine ( temperature scales ) ) ) ) ) ( ( ( use it ) ( as ( their ( zero point ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNP Kelvin) (CC and) (NNP Rankine) (NNP temperature) (NNS scales)) (VP (VBP use) (NP (PRP it)) (PP (IN as) (NP (PRP$ their) (CD zero) (NN point)))) (. .)))
The Kelvin and Rankine temperature scales use it as their zero point.
(ROOT (S (NP (DT The) (JJ kelvin) (NN scale) (NN temperature) (NN scale)) (VP (VBZ is) (ADVP (RB commonly)) (VP (VBN used) (PP (IN in) (NP (NN science))))) (. .)))