(S (S (BASENP (DT This)) (VP (VBD was) (VP (VP (VBN followed) (PP (IN by) (NP (BASENP (DT a) (NN demonstration)) (PP (IN of) (NP (BASENP (DT the) (NN sport)) (PP (IN by) (NP (NP (NP (BASENP (DT the) (NNP Lord) (NNP Mayor)) (PP (IN of) (BASENP (NNP London)))) (BASENP (NNP Boris) (NNP Johnson))) (CC and) (BASENP (JJ British) (NN actress) (NNP Barbara) (NNP Windsor))))))))) (COMMA ,) (PP (IN with) (S (BASENP (DT the) (NN arena) (NN commentator)) (VP (VBG noting) (SBAR (S (BASENP (NNP Johnson)) (VP (VBZ is) (BASENP (DT a) (ADJP (RB surprisingly) (JJ good)) (NN player))))))))))) (PERIOD .))