帕累托原则…原因指出，对许多事件，大约80％的效果来从20％。

The Pareto principle… states that, for many events, roughly 80% of the effects come from 20% of the causes.

youdao

The trouble is, you just don't know when that explosion took place, and since there are several periods in this general area that we're talking about now, in which something big happened, some great change takes place, it turns out different people want to have their explosion at different times.

问题是,你不了解火山爆发的,确切时间以及这种爆发,在这个区域又延续了很多个时期,这些时期发生了许多重大事件和重大变化,结果就是不同人对,火山爆发的时间推测各不相同

耶鲁公开课 - 古希腊历史简介课程节选