英语语法分析

Map this number to the Roman numeral system.

将这个数字映射到罗马数字系统。

For instance, take a number from the Arabic numeral system, such as 9.

例如，从阿拉伯数字系统中取出一个数字，比如说 9。

Now map that back to the Arabic numeral system and you end up with, no surprise, 9.

现在把它映射回阿拉伯数字系统，毫无疑问，你会得到9。