Isaac had found the work unendurable and walked out of the job.

艾萨克觉得这份工作无法忍受就辞职了。

His impatience to get to London grew hourly, and his captivity became almost unendurable.

他越来越急切地要到伦敦去，他被囚禁的日子几乎到了难以忍受的地步。

What is it that I especially find utterly unendurable?

什么东西是我完全无法忍受的？

The pressure inside the old submarine was almost unendurable.

老式潜艇内的压力几乎是难以忍受的。

I felt the long, spread out boredom ahead of me to be almost unendurable.

我觉得面前漫长的无聊生涯简直难以忍受。