And we don't know exactly how they did this, although they must have solved some collective action problems; it only makes sense that you can't hunt mastodons while you're fighting with the other groups.
我们不确定他们当时是如何做到的。 不过他们一定解决了某些集体行动上的问题。 当你猎杀乳齿象时， 不能和其他组织争斗，这样才说的通。