我们勿忘历史对我们的教训。

Wǒmen wùwàng lìshǐ duì wǒmen de jiàoxùn.

We must not forget the lessons history has taught us.

我走了，勿念。

Wǒ zǒu le, wù niàn.

I’m leaving—don’t miss me.

考试进行中，勿打扰。

Kǎoshì jìnxíng zhōng, wù dǎrǎo.

Exam in progress. Do not disturb.