Marx produced a new theory about historical change based upon conflict between competing groups.

马克思提出了一个新理论，认为历史变革是由于对立集团的冲突而产生的。

《柯林斯英汉双解大词典》

The Freudian theory about daughters falling in love with their father has little evidence to support it.

弗洛伊德关于女儿恋父的理论没有什么证据来证实。

《柯林斯英汉双解大词典》

There is a more violent theory about how planets form.

关于行星是如何形成的，还有一种更为激烈的理论。

youdao

The most interesting theory about the Lost Colony started with a rock found in nineteen thirty-seven.

VOA: special.2009.08.17

And he has a theory about early life and perfectly appropriate as far as one can tell of what pre-human form he studied.

他有一个有关早期生命的理论,一般人都会觉得很正常,他研究人类之前的生命形式没有什么不合适。

普林斯顿公开课 - 人性课程节选

Well, so I mean, he is... when he invented all the theory about the space time and all this,

嗯，他呢……他发明所有这些空间时间理论的时候，

以爱因斯坦为榜样 - SpeakingMax英语口语达人

Texas pastor Mark Roberts offered an intriguing theory about the congressman's misuse of the Web.

WSJ: Crovitz: The Internet Lets It All Hang Out

But here's our unscientific theory about why you shouldn't bet on a sports-crazed executive.

FORBES: Firms That Buy Teams Tend To Underperform

To prove the theory about microspeeds in search, Google has also deliberately slowed its service.

FORBES: Magazine Article