手机已经成为过去半个世纪中最有用的设备之一。

Cell phones have become one of the most useful devices in the past half century.

你觉得学哪种外文最有用？

Which foreign language do you think is the most useful to learn?

一把好刀可能是厨房里最有用的东西之一。

A good knife is probably one of the most useful things you can have in a kitchen.

最有用的是补丁功能。

The most useful is the patch function.

灯泡是最有用的发明之一。

The light bulb is one of the most useful inventions.

这条建议也许是最有用的。

Start small. This is perhaps the most useful suggestion of all.

柴油是井场上最有用的燃料。

Diesel oi1 is the most useful fuel on the location.

有限元 法 是最有用的方法。

The finite-element method is the most versatile.

我认为最有用的发明是电灯泡。

I think the most helpful invention is the light bulb.

这可是这份报纸最有用的部分了。

That was one of the most useful parts of it.