1.work at

从事于……，致力于……；钻研

eg.Tom has been working at the subject for many years.
汤姆已经钻研这门学科多年。

在……工作，在……任职

eg.Have you ever been working at the bank?
你在银行工作过吗?

2.hopelessadj.绝望的；不可救药的

原文：It was hopeless to ask any more questions.

eg.We have to charge off the debt as hopeless.
我们只好把这笔债款作为无望收回而注销。

eg.None of us are hopeless and we all have the power within ourselves to recover.
我们中没有人是无望的，我们都可以从我们身上找到力量去复原。

eg.I'm hopeless at this myself, but I expect we'll all get better at this in the future.
我自己在这方面是不可救药了，但我希望未来我们都能在这方面做得更好。