本文还讨论了如何使用在前面几期文章中介绍的一些工具，以便对您的系统进行更改。
It also discusses how to use several of the tools illustrated in prior installments to make changes to your systems.
前面几期文章曾多次提到，模型不是凭空而来的，建立模型是为了服务于特定的目的。
As I have stated many times in this series, a model is not drawn in a vacuum; it is created to serve a specific purpose.
应用推荐