But you must not forget it.

可是你不应将它遗忘。

youdao

But you must not eat the blood; pour it out on the ground like water.

只是不可吃血，要倒在地上，如同倒水一样。

youdao

Yep, you'd like to say something to her like that, but you must not. Why not?

是的，你可能很想对她说这样的话，但你一定不要说，为什么不呢？

youdao

You must have let your phone dieor something. I'm not in Forks, but everything's okay,and I'll explain it later.

VOA: standard.other

He replied, "Jacob." Said he, "Your name shall no longer be Jacob, but Israel, for you have striven with God and men, and have prevailed." Jacob asked, "Pray tell me your name." But he said, "You must not ask my name!"

答，“我名叫雅各，“那人说，“你的名不要再叫雅各,要叫以色列，因为你与神与人较力都得了胜，“雅各问,“请将你的名告诉我，“那人却说，“何必问我的名，“

耶鲁公开课 - 旧约导论课程节选

You can also use a "must" pattern when you're not talking about a person but you're talking about a situation.

当你不在谈论人物，而是在谈论情况的时候，你也可以用“must”句型。

Must 课堂 - SpeakingMax英语口语达人

But you must not forget that gold is still precious to two billion Chinese and Indians.

CNN: Money & Investing

But you must not indicate that you are in the know.

NEWYORKER: Pumpkin Head

You can make money on hot growth stocks, but you must be wary of them in a way that you do not have to be wary of a low-multiple value stock.

FORBES: Priced For Perfection