(S (S (S (BASENP (DT Some) (NNS videos)) (VP (ADVP (RB even)) (VP (VBD showed) (S (BASENP (PRP him)) (VP (VBG wearing) (BASENP (DT an) (NN oxygen) (NN mask))))))) (SBAR (IN while) (S (BASENP (PRP he)) (VP (VBD was) (VP (VBG performing) (BASENP (PRPD his) (NN sermon))))))) (PERIOD .))