( ( In ( other words ) ) ( , ( ( every year ) ( ( the earth ) ( ( ( goes ( around ( the sun ) ) ) once ) . ) ) ) ) )
(ROOT (S (PP (IN In) (NP (JJ other) (NNS words))) (, ,) (NP (DT every) (NN year)) (NP (DT the) (NN earth)) (VP (VBZ goes) (PP (IN around) (NP (DT the) (NN sun))) (ADVP (RB once))) (. .)))
In other words, every year the earth goes around the sun once.
(ROOT (S (NP (NNP Earth)) (VP (VBZ makes) (NP (DT a) (JJ complete) (NN revolution)) (NP (ADVP (IN around) (NP (DT the) (NN sun)) (PP (IN about) (ADVP (RB once)))) (DT every) (NN year))) (. .)))