(S (S (S (BASENP (NNS Marches)) (VP (VP (VBD took) (BASENP (NN place))) (PP (IN near) (BASENP (DT the) (ADJP (JJ Saudi) (JJ Arabian)) (NN embassy))))) (COMMA ,) (PP (IN with) (S (BASENP (NNS protesters)) (VP (VP (VBG wearing) (BASENP (NNS masks))) (PP (IN as) (NP (BASENP (DT a) (NN defense)) (PP (IN against) (BASENP (NN tear) (NN gas))))))))) (PERIOD .))