My mobile phone is extremely useful.

我的手机极为有用。

《柯林斯英汉双解大词典》

It was a collaboration that produced extremely useful results.

这是一次带来极其有益的成果的合作。

《牛津词典》

Anything that can increase farming efficiency—the amount of crops we can produce per acre of land—will be extremely useful.

任何能提高农业效率的东西——能提高我们每英亩土地生产的农作物数量的东西——都是非常有用的。

youdao

And this is extremely useful when it comes to filling in gaps in sounds.

当需要在声音中填入间隔时,自上而下加工是非常有效的

耶鲁公开课 - 心理学导论课程节选

Extremely useful still for freight but less so for the movement of people over long distances.

FORBES: China's Now The Top Market For Connected Smartphones And Tablets

This is another aspect of the doddle platform that is extremely useful to people.

FORBES: Doddle Of The Dead - Putting The App In Zombie Apocalypse, Part 2

We just completed a prolonged and extremely useful conversation touching on a wide range of issues.

WHITEHOUSE: President Obama Meets with Prime Minister Netanyahu