(S (S (BASENP (NNPS Arabs)) (VP (VP (VBP constitute) (NP (NP (BASENP (NN one)) (BASENP (NN fifth))) (PP (IN of) (NP (BASENP (DT the) (NN population)) (PP (IN in) (BASENP (NNP Israel))))))) (CC but) (VP (ADVP (RB only)) (VP (VBP have) (NP (BASENP (NN twelve)) (PP (IN of) (BASENP (NN 120) (JJ parliamentary) (NNS seats)))))))) (PERIOD .))