下列类定义中哪些是合法的抽象类的定义?() abstract Animal{abstract void growl();} class abstract Animal{abstract void growl();} abstract class Animal{abstract void growl();} abstract class Animal{abstract void growl(){System.out.println( “growl”);};}
abstract Animal{abstract void growl();}
class abstract Animal{abstract void growl();}
abstract class Animal{abstract void growl();}
abstract class Animal{abstract void growl(){System.out.println( “growl”);};}