( ( ( The top ) ( of ( the mesosphere ) ) ) ( ( is ( called ( the mesopause ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN top)) (PP (IN of) (NP (DT the) (NN mesosphere)))) (VP (VBZ is) (VP (VBN called) (NP (DT the) (NN mesopause)))) (. .)))
The top of the mesosphere is called the mesopause .
(ROOT (S (NP (DT The) (NN mesopause)) (VP (VBZ is) (PP (IN at) (NP (NP (DT the) (NN top)) (PP (IN of) (NP (DT the) (NN mesosphere)))))) (. .)))