if at any point you've got something you want to ask about or some two bits you want to add, raise your hand, wiggle it around, make sure I see you.

任何时刻如果你有想问的东西,或者你想要加上什么东西，请举手，摇晃起来，确保我能看见。

耶鲁公开课 - 死亡课程节选