现有: <br /> interface Animal {      <br /> void eat () ;      <br /> }      <br /> //insert code here      <br /> public class HouseCat extends Feline {      <br /> public void eat() { }      <br /> } <br /> 和五个申明 <br /> abstract class Feline implements Animal { } <br /> abstract  class  Feline  implements  Animal  {  void eat () ;  } <br /> abstract class Feline implements Animal { public void eat();} <br /> abstract class Feline implements Animal { public void eat() {}  } <br /> abstract&
A、1
B、2
C、3
D、4