Reflective essays explore what the author believes and the origins of those beliefs. Which sentences in this excerpt from Amy Tan's "Mother Tongue" indicate where Tan’s beliefs came from?

You should know that my mother's expressive command of English belies how much she actually understands. She reads the Forbes report, listens to Wall Street Week, converses daily with her stockbroker, reads all of Shirley MacLaine’s books with ease—all kinds of things I can't begin to understand. Yet some of my friends tell me they understand fifty percent of what my mother says. Some say they understand eighty to ninety percent. Some say they understand none of it, as if she were speaking pure Chinese. But to me, my mother's English is perfectly clear, perfectly natural. It's my mother tongue. Her language, as I hear it, is vivid, direct, full of observation and imagery. That was the language that helped shape the way I saw things, expressed things, made sense of the world.