The LANG environment variable is used to set the default locale for all categories, but LC_* variables can be used to override individual categories.

我们用 LANG 环境变量为所有类别设置缺省语言环境，但 LC_* 变量可以用来覆盖单个类别。

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These are also considered variable because you can cut back on how much you spend on these categories if you need to.

这些列为可变是因为一旦需要节省开支，这一类支出是可以改变的。

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