They are completely outworn and exhausted.

他们极度疲惫不堪，筋疲力尽。

Every historian — sometimes unconsciously, but always inevitably — must have put to himself the question: How long could such-or-such an outworn system last?

位历史学家——有是不自觉， 但总是不可避免——都必须向自己提出这样个问题：这样或那样系统能持续多久？

But even as they drew near the fences at last she closed her staring eyes, and would sleep; and they laid her down, and rested also, unheedfully, for they were utterly outworn.

可是，即使他们快走近栅栏，她终于闭上了瞪着眼睛，睡着了。他们就把她放，也懒洋洋休息了，因为他们已经完全疲惫不堪了。