( ( At ( ( the beginning ) ( of ( last semester ) ) ) ) ( , ( chemistry ( ( was ( defined ( as ( ( ( ( the study ) ( of matter ) ) and ) ( ( the changes ) ( it undergoes ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN At) (NP (NP (DT the) (NN beginning)) (PP (IN of) (NP (JJ last) (NN semester))))) (, ,) (NP (NN chemistry)) (VP (VBD was) (VP (VBN defined) (PP (IN as) (NP (NP (NP (DT the) (NN study)) (PP (IN of) (NP (NN matter)))) (CC and) (NP (NP (DT the) (NNS changes)) (SBAR (S (NP (PRP it)) (VP (VBZ undergoes))))))))) (. .)))
At the beginning of last semester, chemistry was defined as the study of matter and the changes it undergoes.
(ROOT (S (NP (NNP Chemistry)) (VP (VBZ is) (VP (VBN defined) (PP (IN as) (NP (NP (DT the) (NN study)) (PP (IN of) (NP (NN matter))))))) (. .)))