( ( ( A connection ) ( between ( ( ( ( the risk ) ( of skin-cancer ) ) and ) ( ( the exposure ) ( to ( ultraviolet radiation ) ) ) ) ) ) ( ( is ( scientifically ascertained ) ) . ) )
(ROOT (S (NP (NP (DT A) (NN connection)) (PP (IN between) (NP (NP (NP (DT the) (NN risk)) (PP (IN of) (NP (NN skin-cancer)))) (CC and) (NP (NP (DT the) (NN exposure)) (PP (TO to) (NP (JJ ultraviolet) (NN radiation))))))) (VP (VBZ is) (ADJP (RB scientifically) (JJ ascertained))) (. .)))
A connection between the risk of skin-cancer and the exposure to ultraviolet radiation is scientifically ascertained.
(ROOT (S (NP (NP (NNP Exposure)) (PP (TO to) (NP (JJ ultraviolet) (NN radiation)))) (VP (MD can) (VP (VP (VB increase) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NN pigment)))) (PP (IN in) (NP (DT the) (NN skin)))) (CC and) (VP (VB make) (S (NP (PRP it)) (VP (VB appear) (NP (JJR darker))))))) (. .)))