( Currently ( ( ( only ( the continents ) ) ( of ( ( ( ( ( ( North America ) , ) Australia ) , ) and ) Antarctica ) ) ) ( ( are ( free ( of ( the disease ) ) ) ) . ) ) )
(ROOT (S (ADVP (RB Currently)) (NP (NP (RB only) (DT the) (NN continents)) (PP (IN of) (NP (NP (NNP North) (NNP America)) (, ,) (NP (NNP Australia)) (, ,) (CC and) (NP (NNP Antarctica))))) (VP (VBP are) (ADJP (JJ free) (PP (IN of) (NP (DT the) (NN disease))))) (. .)))
Currently only the continents of North America, Australia, and Antarctica are free of the disease.
(ROOT (S (NP (NNP Antarctica)) (VP (VBZ is) (NP (NP (DT the) (JJ only) (NN continent)) (PP (IN without) (NP (NNS amphibians))))) (. .)))