白费 的中文句子和英文句子

他们不管事, 我们为改进工作的用心也就白费了.

Their unhelpfulness has stultified our efforts to improve things.


我们想使他改变主意，结果是白费心机。

We tried in vain to make him change his mind.


他的所有努力都白费了。

All his efforts were wasted.