You must keep silent during the exam.

考试时你必须保持沉默。

youdao

You must keep silent about the matter.

你必须对此事保持沉默。

youdao

You must learn when to speak and when to keep silent.

你必须学会什么时候讲话，什么时候沉默。

youdao

You must learn when to speak and when to keep silent.

你必须学会什么时候讲话，什么时候沉默。

youdao