That sounds simple. But the issue is a complex mix of technical,business, political and legal questions.

VOA: special.2009.09.25

So it's a complex issue, and I should leave it having said this much, at least for the moment.

因此它是一个很复杂的问题，而我就讲到这里，至少暂时这样。

耶鲁公开课 - 文学理论导论课程节选

We can already use that in terms of single ions to think about a really complex biological issue, which is to talk about ion channels.

我们已经能够仅仅凭借这个关于单个离子的原理,来讨论一个非常复杂的生物问题了，我们要讨论的就是离子通道。

麻省理工公开课 - 化学原理课程节选