You feel physiologically aroused but you're not completely sure why, and you have to make up an explanation for it.

你感觉到性觉醒,但是不能确定是什么原因，你不得不给出一个解释。

耶鲁公开课 - 心理学导论课程节选

One of the reasons for thinking it's not clear whether the argument fails or not is because it's hard to pin down, where exactly did it go wrong?

并不能确定这个论证是否成立,的其中一个原因就是,我们很难确定,到底是哪里出了问题

耶鲁公开课 - 死亡课程节选

You'd be hard pressed to identify what the meter of that is so that's one reason, and of course what--where am I going with the next important point about what's happening in this music?

你会很难确定其中的节拍,这也是原因之一,当然这也是我将要讲解的下个关键点,关于在这类音乐中的情形

耶鲁公开课 - 聆听音乐课程节选