( ( The lathe ) ( ( can ( shape ( either ( a ( convex ( or ( concave lens ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN lathe)) (VP (MD can) (VP (VB shape) (PP (CC either) (NP (DT a) (NN convex) (CC or) (NN concave) (NN lens))))) (. .)))
The lathe can shape either a convex or concave lens.
(ROOT (S (NP (DT The) (ADJP (RBS most) (JJ common)) (JJ two-lens) (NN telescope)) (, ,) (PP (IN like) (NP (DT the) (JJ simple) (NN microscope))) (, ,) (VP (VBZ uses) (NP (NN convex) (NNS lenses))) (. .)))