answer: Mary tells #Person1# what #Person1# saw #Person1#'s Indian classmate doing last night is Indian Yoga and introduces it to #Person1#.
documents: #Person1#: Last night I looked for my Indian classmate Barbara. I found her sitting with her legs crossed and quietly practicing.
  #Person2#: Needless to say, it must be Indian Yoga.
  #Person1#: Mary, you say something about it.
  #Person2#: Tracing back, Yoga has a very long history. It was originated before India had approved Yoga and these documents were arranged and written according to the contents passed by mouth to mouth. In other words, Yoga is passed down from ancient times, which cannot be recalled.