Useful numbers常用电话号码;常用电话;常用德律风号码;经常使用电话号头
useful resistance有益阻力
useful work[机] [物] 有用功;有效功;讨论;有用功
Useful lists常用表达
Useful Phrases零存整取;常见搭配;有用短语;有用的短语
useful volume有效容积;有用容积;实用容积
Useful Sentences第三节;常用句型;实用例句;实用句型
useful radiation有用辐射;有效辐射
ADJ（形容词） If something is useful, you can use it to do something or to help you in some way. 有用的
The pressure cooker is very useful for people who go out all day.
压力锅对整天外出的人非常有用。
ADV（副词） usefully 有用地 [ADV with v]
...the problems to which computers could be usefully applied.
…可以应用计算机来解决的问题。
PHRASE（习语） If an object or skill comes in useful, it can help you achieve something in a particular situation. 有用
Extra blank paper will probably come in useful.
额外的空白纸可能用得着。