billion是什么意思?

billion的中文含义详细解释：
num.&n. 十亿
billion的列举例句：
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。