( ( This star ) ( ( must ( be ( the ( last ( star ( to ( be ( classified ( as ( a ( circumpolar star ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT This) (NN star)) (VP (MD must) (VP (VB be) (NP (DT the) (JJ last) (NN star) (S (VP (TO to) (VP (VB be) (VP (VBN classified) (PP (IN as) (NP (DT a) (NN circumpolar) (NN star)))))))))) (. .)))
This star must be the last star to be classified as a circumpolar star.
(ROOT (S (NP (DT The) (NN sun)) (VP (VBZ is) (VP (VBN classified) (PP (IN as) (NP (DT a) (NN star))))) (. .)))
The sun is classified as a star.