( Thus ( , ( ( ( ( ( ( the speed ) ( of ( sound ( through ( a medium ) ) ) ) ) , ) ( such ( as ( ( air or ) water ) ) ) ) , ) ( ( is ( determined ( by ( ( the properties ) ( of ( that medium ) ) ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB Thus)) (, ,) (NP (NP (DT the) (NN speed)) (PP (IN of) (NP (NP (NN sound)) (PP (IN through) (NP (DT a) (NN medium))))) (, ,) (PP (JJ such) (IN as) (NP (NN air) (CC or) (NN water))) (, ,)) (VP (VBZ is) (VP (VBN determined) (PP (IN by) (NP (NP (DT the) (NNS properties)) (PP (IN of) (NP (DT that) (NN medium))))))) (. .)))
Thus, the speed of sound through a medium, such as air or water, is determined by the properties of  that medium.
(ROOT (S (NP (NP (DT The) (NN speed)) (PP (IN of) (NP (NN sound)))) (VP (VBZ depends) (PP (IN on) (NP (NN medium)))) (. .)))
The speed of sound depends on medium.