( Only ( ( ( Antarctica and ) Australia ) ( ( remain ( isolated ( island continents ) ) ) . ) ) )
(ROOT (S (RB Only) (NP (NNP Antarctica) (CC and) (NNP Australia)) (VP (VBP remain) (NP (JJ isolated) (NN island) (NNS continents))) (. .)))
Only Antarctica and Australia remain isolated island continents.
(ROOT (S (NP (NNP Antarctica)) (VP (VBZ is) (NP (NP (DT the) (JJ only) (NN continent)) (PP (IN without) (NP (NNS amphibians))))) (. .)))