We need double the amount we already have.

我们需要现有数量的两倍。

《牛津词典》

They were travelling at a speed that was double the legal limit.

他们正以两倍于法定限速的速度行驶。

《牛津词典》

youdao

It predicts counterfeit sales will reach seventy-five billion dollars worldwide this year nearly double the level of two thousand five.

VOA: special.2010.02.22

I mean that's obvious. The mass, if you double the amount of stuff the mass will double.

这是显然的，还有质量，如果你把系统中物质的,数量增加一倍，质量也会增加一倍。

麻省理工公开课 - 热力学与动力学课程节选

If you double the system, they double in there numerical number.

如果你把系统扩大一倍，它们的值也会扩大一倍。

麻省理工公开课 - 热力学与动力学课程节选

It is also home to around 16, 000 bird species, double the number in all Europe.

BBC: Hot springs and hummingbirds in Ecuador

In services, foreign-owned companies generated double the value added per worker, and had labour costs 30% higher.

BBC: Who owns the best of Scotland?

United Airlines had the highest complaint rate, almost double the prior year, while Southwest had the lowest.

BBC: Virgin tops US airline industry report