I mean, this is a crisis that's crossing international boundaries.

我的意思是，这一危机跨越了国际边界。

I think this one crosses cultural, international boundaries.

我认为这跨越了文化和国际界限。

Scientists are talking to each other across international boundaries without any questions.

科学家们正在跨越国界相互交谈，没有任何问题。

I am thinking when humor crosses international boundaries, the first obstacle it encounters is translation.

我在想当幽默跨越国际边界时，它遇到的第一个障碍就是翻译。

Then, the pathogen has to spread widely, crossing international boundaries and infecting lots of people.

然后，病原体必须广泛传播，跨越国界并感染很多人。

Rivers, which make up over a third of the length of all international land boundaries will be subject to extreme events that can change their course.

占所有国际陆地边界长度三分之一以上的河流，将受到极端事件的影响，可能改变它们的流向。