That's almost one fifth of the world's population.

这几乎是世界人口的五分之一。

How fast is the world's population growing?

世界人口增长有多快？

About 30% of the world's population is overweight.

世界上大约30%的人口超重。

What else do you know about the world's population?

你还知道关于世界人口的什么？

I'm preparing a report called The world's population.

我正在准备一份名为“世界人口”的报告。

I am preparing a report called The world's population.

我在准备一篇题为“世界人口”的报告。

If 1.75 billion is a quarter of the world's population, what's the whole population of the world?

如果17.5亿是世界人口的四分之一，那么世界总人口是多少？

It said the world's population was about 7.8 billion in 2020.

据说2020年世界人口约为78亿。

English is now used by nearly a quarter of the world's population.

英语现在被世界上近四分之一的人使用。

The world's population has exceeded one billion.

世界人口已经超过十亿。