billion

num.&n. 十亿

It took them more than one billion dollars to complete the project.

完成这个工程花费了他们十亿多美元。

The human brain contains several billion nerve cells, which are connected with one another by fine nerves.

人类的大脑含有几十亿个神经细胞，这些细胞由纤细的神经将彼此连接起来。