Don't expend all your time on such a useless job.

不要把时间消耗在这种无用的工作上。

They weeded out useless books from library.

们从图书室淘汰无用的书。

She could see the utter futility of trying to protest.

她明白抗议是完全无用的。

This top fermented Trappist beer, refermented in the bottle, is not pasteurised.

这个修道院啤酒，在瓶酵的，无用巴氏法灭。

This is a waste and useless tyre.

这是个废弃无用的。

He made it a useless attempt to advise her.

认为试图劝她是无用的。

Unemployed people often feel they've been left on the shelf.

失业的人常感到自己是个无用的人。

When I asked the company what their policy was on this matter, I received a very dusty answer.

我问这家公司对这件事采取什么政策，结果得到了一个毫无用处的回答。

He is a total incompetent.

是个全无用处的人。;是一个毫无能力的人。