class Animal { public Animal() { System.out.println("Animal!"); } } public class Dog extends Animal{ public Dog() { System.out.println("Dog!"); } public static void main(String[] args) { Dog dog=new Dog(); } }

下列程序运行结果是( ) public class Demo { public static void main(String[] args) { Demo demo = new Demo(); demo.show(new Car() { public void run() { System.out.println("demo run"); } }); } public void show(Car c) { c.run(); } }abstract class Car { public void run() { System.out.println("car run..."); } }

Java程序如下 class A{ public A(){System.out.print("A");} } class B extends A{ public B(){System.out.print("B");} public static void main(String[]s){ new B(); } } 该程序将（ ）。

abstract class BaseClass { public virtual void MethodA() { } public virtual void MethodB() { } } class Class1: BaseClass { public void MethodA(string arg){ } public override void MethodB(){ } } class Class2: Class1 { new public void MethodB(){ } } class MainClass { public static void Main(string[] args) { Class2 o = new Class2(); Console.WriteLine(o.MethodA()); } } 请问，o.MethodA调用的是 A: BaseClass.MethodA B: Class2.MethodA C: Class1.MethodA D: 都不是

Which two allow the class Thing to be instantiated using new Thing（）？ A:  public class Thing { } B:  public class Thing { public Thing（） {} } C:  public class Thing { public Thing（void） {} } D:  public class Thing { public Thing（String s） {} } E:  public class Thing { public void Thing（） {} public Thing（String s） {} }