It's there. And what you need to say is what can I do to help?

VOA: standard.2009.12.04

So we need to revise our account of what it is on the physicalist picture to say that you're dead.

我们应该重新修改一下,物理主义学上对死亡的定义。

耶鲁公开课 - 死亡课程节选

When you say "I must" what you mean is "I need to do something."

当你说 "I must"的时候，你是指“我必须得做某事。”

Must 课堂 - SpeakingMax英语口语达人

You need to listen to what your classmates are saying and say why you disagree with them.

你需要去听你的同学在说什么,跟为什么你和他们意见不一。

耶鲁公开课 - 死亡课程节选