( ( Perhaps one ) ( ( chooses ( to ( ( ( ( classify ( with respect ) ) ( to ( physical features ) ) ) , ) ( like ( colour ( of ( skin ( for example ) ) ) ) ) ) ) ) ; ) )
(ROOT (S (NP (RB Perhaps) (CD one)) (VP (VBZ chooses) (S (VP (TO to) (VP (VB classify) (PP (IN with) (NP (NN respect))) (PP (TO to) (NP (JJ physical) (NNS features))) (, ,) (PP (IN like) (NP (NP (NN colour)) (PP (IN of) (NP (NP (NN skin)) (PP (IN for) (NP (NN example))))))))))) (: ;)))
Perhaps one chooses to classify with respect to physical features, like colour of skin for example;
(ROOT (S (NP (NP (NNP Dry) (NN skin)) (CC and) (NP (NNS scales))) (VP (VBP are) (NP (NP (NN part)) (PP (IN of) (NP (NP (DT an) (NN animal)) (SBAR (WHNP (WDT that)) (S (VP (MD would) (ADVP (RBS most) (RB likely)) (VP (VB be) (VP (VBN classified) (PP (IN as) (NP (DT a) (NN reptile)))))))))))) (. .)))