答案:abstract class BaseClass { public virtual void MethodA() { Console.WriteLine('BaseClass' } public virtual void MethodB() { } } class Class1 : BaseClass { public void MethodA() { Console.WriteLine('Class1'); } public override void MethodB() { } } class Class2 : Class1 { new public void MethodB() { } } class MainClass { public static void Main(string[] args) { Class2 o = new Class2(); o.MethodA(); } }