( ( Thinning ( Skin ( To ( see ( ( the effect ) ( of ( the sun ) ) ) ) ) ) ) ( , ( doctors ( ( have ( looked ( at ( what ( happens ( to ( ( the ( outer ( two layers ) ) ) ( of ( ( ( ( skin , ) ( the dermis ) ) and ) ( the epidermis ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (S (VP (VBG Thinning) (S (NP (NNP Skin)) (VP (TO To) (VP (VB see) (NP (NP (DT the) (NN effect)) (PP (IN of) (NP (DT the) (NN sun))))))))) (, ,) (NP (NNS doctors)) (VP (VBP have) (VP (VBN looked) (PP (IN at) (SBAR (WHNP (WP what)) (S (VP (VBZ happens) (PP (TO to) (NP (NP (DT the) (JJ outer) (CD two) (NNS layers)) (PP (IN of) (NP (NP (NN skin)) (, ,) (NP (DT the) (NNS dermis)) (CC and) (NP (DT the) (NNS epidermis)))))))))))) (. .)))
Thinning Skin To see the effect of the sun, doctors have looked at what happens to the outer two layers of skin, the dermis and the epidermis.
(ROOT (S (NP (DT The) (NN skin)) (VP (VBZ is) (VP (VBN made) (PP (IN of) (NP (NP (CD two) (NNS layers)) (: :) (NP (NNS epidermis) (CC and) (NNS dermis)))))) (. .)))