你发布的第一个答案（系统是一个内置类.. 。）非常适合。

The first answer you posted (System is a built-in class...) is pretty spot on.

您可以添加系统类包含大部分本机和由JVM在启动期间设置，例如将 System.out printstream连接到与标准输出（控制台）关联的本机输出流。

You can add that the System class contains large portions which are native and that is set up by the JVM during startup, like connecting the System.out printstream to the native output stream associated with the "standard out" (console).