( ( ( Magnitudes , ) ( ( ( ( Colors , ) ( the ( HR Diagram ) ) ) and ) ( the ( Distance ( Modulus ( Define ( apparent ( magnitude ( and ( absolute magnitude ) ) ) ) ) ) ) ) ) ) . )
(ROOT (NP (NP (NNS Magnitudes)) (, ,) (NP (NP (NNP Colors)) (, ,) (NP (DT the) (NNP HR) (NNP Diagram)) (CC and) (NP (DT the) (NNP Distance) (NNP Modulus) (NNPS Define) (JJ apparent) (NN magnitude) (CC and) (JJ absolute) (NN magnitude))) (. .)))
Magnitudes, Colors, the HR Diagram and the Distance Modulus Define apparent magnitude and absolute magnitude.
(ROOT (S (NP (NNP Distance)) (VP (VBZ is) (VP (VBN defined) (PP (IN as) (NP (NP (DT the) (NN magnitude) (CC or) (NN size)) (PP (IN of) (NP (NP (NN displacement)) (PP (IN between) (NP (CD two) (NNS positions))))))))) (. .)))