( But ( ( three ( important developments ) ) ( ( made ( ( the ( transmission ( electron microscope ) ) ) ( extremely ( useful ( to ( the biologist ) ) ) ) ) ) . ) ) )
(ROOT (S (CC But) (NP (CD three) (JJ important) (NNS developments)) (VP (VBD made) (S (NP (DT the) (NN transmission) (NN electron) (NN microscope)) (ADJP (RB extremely) (JJ useful) (PP (TO to) (NP (DT the) (NN biologist)))))) (. .)))
But three important developments made the transmission electron microscope extremely useful to the biologist.
(ROOT (S (NP (DT A) (NN electron) (NN microscope)) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB see) (NP (ADJP (RB extremely) (JJ small)) (NNS objects))))))) (. .)))