Two theories exist as to why.

有两种理论解释了其中的原因。

youdao

He offers two theories.

他提出了两个理论。

youdao

There are two theories as to how miners should spread their risks.

矿业公司分散风险的理论有两种。

youdao

If we're going to have a way to decide between these two theories, it seems as though we need some other kind of arguments.

如果我们非要找个方法在两个理论之间取舍，那看来我们需要别的论据。

耶鲁公开课 - 死亡课程节选

So, Hartman and Fish have forwarded two perfectly ingenious theories of Milton's similes, and they've had a tremendous impact, rightly, on generations now of readers of Milton.

所以，哈特曼和费什提出了两个相当聪明的理论,给弥尔顿的两代读者，留下了深远的影响。

耶鲁公开课 - 弥尔顿课程节选

Most theories are specialized theories, but these two views are grand theories.

大多数理论的适用范围都是有所限定的，但这两个理论则是大理论。

耶鲁公开课 - 心理学导论课程节选

This granularity emerges from what is the most important difference between the two theories.

ECONOMIST: A new ��theory of everything�� is gaining ground

Ressi has two theories: As people get older, they gain experience performing increasingly complicated tasks.

FORBES: Can An Hour-Long Aptitude Test Predict Startup Home Runs? Adeo Ressi Thinks So

Investment analysts have two theories on volatility and market performance, and unfortunately they contradict each other.

ECONOMIST: Collywobbles