The back-and-forth informs both apprentice and master; both are learning, though each learn different things.
这一来一去的学习给师徒都带来了启示；所以我们说他们都在学习，虽然每个人学的是不同的东西。
2
Centuries ago, apprenticeships were the preferred method of learning a new craft. Under an experienced tutor, an apprentice will not only study the craft, but will also practice it.