They make up the class of Semantic Clue Elements.
( They ( ( ( make up ) ( ( the class ) ( of ( Semantic ( Clue Elements ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP make) (PRT (RP up)) (NP (NP (DT the) (NN class)) (PP (IN of) (NP (NNP Semantic) (NNP Clue) (NNP Elements))))) (. .)))
They comprise the category of Semantic Clue Elements.
( They ( ( comprise ( ( the category ) ( of ( Semantic ( Clue Elements ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP comprise) (NP (NP (DT the) (NN category)) (PP (IN of) (NP (NNP Semantic) (NNP Clue) (NNP Elements))))) (. .)))