They learn that if you just stare at a student and raise your eyebrow about a quarter of an inch, you don't have to say a word because they know that that means that you want more.
他们学到如果你凝视一个学生 并将你的眉毛抬高四分之一英寸， 你一个字都不用说 因为学生会知道你想要更多的答案。