The noise seems to be coming from within the building.

吵闹声像是从楼房里传出来的。

《牛津词典》

It's easier to "capture the fortress from within."

堡垒更容易从内部攻破。

《新英汉大辞典》

The easiest way to capture a fortress is from within.

堡垒是最容易从内部攻破的。

《新英汉大辞典》

One issue related to that fight is how to deal with the growing threat of terrorism from within the United States.

VOA: special.2009.10.17

So essentially it's something that has to come from within the community, with the support, but it really is an evolution.

所以，从本质上来说，人权观念的改变,必须是在帮助下的群体自发觉悟，而且是一种发展。

普林斯顿公开课 - 人性课程节选

How can it activate the rules of a language from within and thus give rise to the designs which are properly own--its own?"

它又是如何使语言的规则发生作用,并且导致适当的属于自己的设计的？，“

耶鲁公开课 - 文学理论导论课程节选

Compelling content can get shared from within the email itself, which then enables broader social exposure.

FORBES: Has Social Become the New Search?

The biggest backlash came from within China with netizens exposing and criticizing the teenager.

CNN: China instructs its citizens on how to behave abroad

That means the leadership for any action by workers has to come from within each factory.

FORBES: India