billions of

Billions of dollars each year are spent on schools and libraries.(每年有数十亿美元花在建设学校和图书馆上。)

Drug companies have spent billions of dollars searching for therapies to reverse or significantly slow Alzheimer's disease, but in vain.(医药公司已经花费数十亿美元以寻找能逆转或显著减缓阿尔茨海默病的治疗方法，但毫无结果。)

Astrogeologists suspect that these scarps having formed billions of years ago as the planet's surface cooled and shrank.(太空地质学家猜测这些陡坡是在几十亿年前当行星表面冷却收缩时开始形成的。)

The country owes billions of dollars to foreign creditors.(这个国家欠外国债权人数十亿元。)

She faces charges of helping to plunder her country's treasury of billions of dollars.(她面临协从窃取国库中数十亿美元的指控。)

They have these special organs that collect the hydrogen sulfide and carbon dioxide and then transfer it to another organ, where billions of bacteria live.(他们有这些特殊的器官来收集硫化氢和二氧化碳，然后把它们转移到另一个器官，那里有数十亿的细菌。)

The insurance industry will pay out billions of dollars for damage caused by Hurricane Katrina.(保险业将为卡特里娜飓风造成的损失赔付数十亿美元。)

It would seem sensible to seek the source of these in the universe's most conspicuous energy factories: quasars and gamma-ray bursts billions of light-years away from Earth.(在宇宙中最引人注目的能量工厂——距离地球数十亿光年的类星体和伽马射线爆发——中寻找这些物质的来源似乎是明智的。)

We are the products of evolution, and not just evolution that occurred billions of years ago.(我们是进化的产物，并且不仅仅是发生在数十亿年前的进化。)

Over billions of years, the gas was compressed by gravity into galaxies, stars, plants and eventually, even humans.(在数十亿年的时间里，这些气体被引力压缩成星系、恒星、植物，最终甚至变成了人类。)