useful的比较级和最高级

useful的短语

useful for可用于

be useful at熟悉,精通,擅长…

be useful to对…有益

be very useful at精通

useful的例句

They produced two reports, neither of which contained any useful suggestions.

他们提交了两个报告，都没有任何有用的建议。

Stop fussing around and find something useful to do!

别瞎忙活了，找点有用的事干！

Your local library will be a useful source of information.

你们当地的图书馆就是很好的资料来源。

It's a useful introduction to an extremely complex subject.

这是对一门极为复杂的学科的有益入门教程。

She has ten years' useful experience behind her.

她有十年的经验，能派上用场。