( ( ( Describe ( thermal ( ( expansion and ) contraction ) ) ) ( in ( terms ( of ( ( the ( ( arrangement and ) motion ) ) ( of ( ( atoms and ) molecules ) ) ) ) ) ) ) . )
(ROOT (S (VP (VB Describe) (NP (JJ thermal) (NN expansion) (CC and) (NN contraction)) (PP (IN in) (NP (NP (NNS terms)) (PP (IN of) (NP (NP (DT the) (NN arrangement) (CC and) (NN motion)) (PP (IN of) (NP (NNS atoms) (CC and) (NNS molecules)))))))) (. .)))
Describe thermal expansion and contraction in terms of the arrangement and motion of atoms and molecules.
(ROOT (S (NP (DT The) (NN term) (JJ thermal) (NN expansion)) (VP (VBZ is) (VP (VBN used) (S (VP (TO to) (VP (VB describe) (NP (NP (DT the) (NN change)) (PP (IN in) (NP (NN size) (CC or) (NN volume))) (PP (IN of) (NP (NP (DT a) (VBN given) (NN mass)) (PP (IN with) (NP (NN temperature))))))))))) (. .)))