IsA now.

从今天起,把zzxy和newsmth的主id改成IsA

摘一段自己的qmd。

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Do u know what is Is-A ? In knowledge representation and object-oriented programing and design, Is-A is a relationship where one class A is a subclass of another class B (and so B is a superclass of A).In addition, ISA means International Seabed Authority, International Searching Authority, Internal Security Act, Ideological State Apparatus, Industry Standard Architecture, Instruction Set Architecture, Information Security Architecture, etc.