( ( Most ( composite volcanoes ) ) ( ( have ( ( a crater ) ( at ( ( the summit ) ( that ( contains ( ( ( a ( central vent ) ) or ) ( ( a ( clustered group ) ) ( of vents ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJS Most) (JJ composite) (NNS volcanoes)) (VP (VBP have) (NP (NP (DT a) (NN crater)) (PP (IN at) (NP (NP (DT the) (NN summit)) (SBAR (WHNP (WDT that)) (S (VP (VBZ contains) (NP (NP (DT a) (JJ central) (NN vent)) (CC or) (NP (NP (DT a) (JJ clustered) (NN group)) (PP (IN of) (NP (NNS vents)))))))))))) (. .)))
Most composite volcanoes have a crater at the summit that contains a central vent or a clustered group of vents.
(ROOT (S (NP (DT A) (NN crater)) (VP (MD can) (ADVP (RB usually)) (VP (VB be) (VP (VBN found) (PP (IN on) (NP (NP (DT the) (NN top)) (PP (IN of) (NP (JJ composite) (NNS volcanoes)))))))) (. .)))