How do you declare a method on a base class so that it can be overridden in the derived class?

in VB.NET wou should put before the method name "Overridable" to declare that this method can be overrided in sub classes, and in sub class if you want to override that method add "Overrides" before its name and it will be overrided, on the other hand, the C# deals like this too

make is virtual. google inheritence and abstract classes for it

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