( Convection ( ( is ( ( ( ( the rising ) ( of ( hot material ) ) ) and ) ( ( the sinking ) ( of ( ( ( cooler material ) , ) ( ( similar ( to ( ( the process ) ( of water ) ) ) ) boiling ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Convection)) (VP (VBZ is) (NP (NP (NP (DT the) (VBG rising)) (PP (IN of) (NP (JJ hot) (NN material)))) (CC and) (NP (NP (DT the) (NN sinking)) (PP (IN of) (NP (NP (JJR cooler) (NN material)) (, ,) (NP (ADJP (JJ similar) (PP (TO to) (NP (NP (DT the) (NN process)) (PP (IN of) (NP (NN water)))))) (JJ boiling))))))) (. .)))
Convection is the rising of hot material and the sinking of cooler material, similar to the process of water boiling.
(ROOT (S (NP (NNS Rises)) (ADVP (RB then)) (VP (ADVP (RB sinks)) (VBZ does) (NP (NP (JJR deeper) (NN material) (NN cause) (NN convection)) (PP (IN in) (NP (DT the) (NN mantle))))) (. .)))