( ( EM See ) ( ( electron microscope ) . ) )
(ROOT (S (NP (NNP EM) (NNP See)) (VP (VBP electron) (NP (NN microscope))) (. .)))
EM See electron microscope .
(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))))))) (. .)))