( ( ( Draw ( a ray ) ) ( ( tracing sketch ) ( of ( ( a ( refracting telescope ) ) ( showing ( how ( ( the image ) ( is formed ) ) ) ) ) ) ) ) . )
(ROOT (S (VP (VB Draw) (NP (DT a) (NN ray)) (NP (NP (JJ tracing) (NN sketch)) (PP (IN of) (NP (NP (DT a) (VBG refracting) (NN telescope)) (VP (VBG showing) (SBAR (WHADVP (WRB how)) (S (NP (DT the) (NN image)) (VP (VBZ is) (VP (VBN formed)))))))))) (. .)))
Draw a ray tracing sketch of a refracting telescope showing how the image is formed.
(ROOT (S (NP (DT An) (NN image)) (VP (VBZ is) (NP (NP (DT a) (NN copy)) (PP (IN of) (NP (NP (DT an) (NN image)) (VP (VBN formed) (PP (IN by) (NP (NN reflection) (CC or) (NN refraction)))))))) (. .)))