a useful gadget
有用的小器具
It can be useful to write a short summary of your argument first.
先把你的论点纲要写下来可能会有帮助。
He might be useful to us.
我们也许用得上他。
These plants are particularly useful for brightening up shady areas.
这些植物特别有助于让背阴的地方明亮起来。
Don't just sit watching television─ make yourself useful !
别光坐着看电视，帮一下忙吧！
This information could prove useful .
这条信息往后也许有用。
Your knowledge of German may come in useful(= be useful in a particular situation) .
你的德文知识可能会派上用场。
Some products can be recycled at the end of their useful life.
有些产品过了有效使用年限后是可以回收再利用的。
He's a very useful player.
他是个很棒的运动员。
1.有用的,有益的,有效的,有帮助的
2.〈俚〉值得称赞的,精通...的 (at)
1.helpful for doing or achieving something
1.This probably would not be very useful as it would only be possible to everaccess one cache at a time.
这可能并不是很有效，因为在同一时间只有可能存取一个缓存。
2.Different laptops may respond to 'standby' in different ways - in many it is only a temporary state and may not be useful for you.
不同的笔记型电脑有不同的「待机」方式-多数情况下只是一个临时状态，不一定对您有用。
3.And this model is going to be very, very useful for a lot of the things that we'll treat.
这个例子非常有用，他会对我们研究其他东西有所帮助。
4.Like an entertaining satire, the plot and characters of that report offer useful material for contemplation.
像娱乐性讽刺一样，报道的情节和角色提供了很好的使人深思的材料。
5.It is often useful to recognize a particular pattern in text and mark it up.
识别文本中的特定模式并进行标记通常十分有用。
6.Based on what you know of the job market, which of your courses were the most useful? The least?
根据你的了解，学什么课程对于就业最有用？最没有用的课程是？
7.When you live a life of deception you get to be very good at it; a well-constructed lie is a lot more useful than the truth.
当你生活在一个被谎言包围的世界中于是你定会非常善于此；一个有着完美构建的谎言往往要比真话有用的多。
8.But I gave it a chance, because smart people who I trusted told me that it's very useful.
但是我给了它一次机会，因为我信任的那个聪明的家伙告诉我它很有用。
9.However, it is often useful to provide additional constructors.
然而，提供其他构造函数通常十分有用。
10.It could be useful, or at least interesting, to let a utility on my home system keep track of hits to my Web server.
让我的主系统上的某个实用程序跟踪对我的Web服务器的点击率，这可能十分有用，至少非常有趣。