public class Alpha{&e

第1题：

public class SomeException {  } Class a：  public class a {  public void doSomething（） { }  } Class b：  public class b extends a {  public void doSomething（） throws SomeException { }  }  Which is true about the two classes？（） 

• A、 Compilation of both classes will fail.
• B、 Compilation of both classes will succeed.
• C、 Compilation of class a will fail. Compilation of class b will succeed.
• D、 Compilation of class a will fail. Compilation of class a will succeed.

第2题：

interface Data { public void load（）； }  abstract class Info { public abstract void load（）； }  Which class correctly uses the Data interface and Info class？（） 

• A、 public class Employee extends Info implements Data { public void load（） { /*do something*/ } }
• B、 public class Employee implements Info extends Data { public void load（） { /*do something*/ } }
• C、 public class Employee extends Info implements Data { public void load（） { /*do something */ } public void Info.load（） { /*do something*/ } }
• D、 public class Employee implements Info extends Data { public void Data.load（） { /*dsomething */ } public void load（） { /*do something */ } }
• E、 public class Employee implements Info extends Data { public void load（） { /*do something */ } public void Info.load（）{ /*do something*/ } }
• F、 public class Employee extends Info implements Data{ public void Data.load（） { /*do something*/ } public void Info.load（） { /*do something*/ } }

第3题：

第4题：

Which two demonstrate an “is a” relationship？（）   

• A、 public interface Person { }  public class Employee extends Person { }
• B、 public interface Shape { }  public class Employee extends Shape { }
• C、 public interface Color { }  public class Employee extends Color { }
• D、 public class Species { }  public class Animal （private Species species；）
• E、 interface Component { }  Class Container implements Component （ Private Component[ ] children；  ）

第5题：

interface Animal {  void soundOff（）；  }  class Elephant implements Animal {  public void soundOff（） {  System.out.println（“Trumpet”）；  }  }  class Lion implements Animal {  public void soundOff（） { System.out.println（“Roar”）；  }  }  class Alpha1 {  static Animal get（ String choice ） {  if （ choice.equalsIgnoreCase（ “meat eater” ）） {  return new Lion（）；  } else {  return new Elephant（）；  }  }  }  Which compiles？（）  

• A、 new Animal（）.soundOff（）；
• B、 Elephant e = new Alpha1（）；
• C、 Lion 1 = Alpha.get（“meat eater”）；
• D、 new Alpha1（）.get（“veggie”）.soundOff（）；

第6题：

Which three demonstrate an “is a” relationship？（） 

• A、 public class X {  }     public class Y extends X { }
• B、 public interface Shape { }     public interface Rectangle extends Shape{ }
• C、 public interface Color { }     public class Shape { private Color color； }
• D、 public interface Species { }     public class Animal { private Species species； }
• E、 public class Person { }    public class Employee {      public Employee（Person person） { }
• F、 interface Component { }     class Container implements Component {   private Component[] children； }

第7题：

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） {} }

第8题：

第9题：

Which the two demonstrate an “is a” relationship？（）

• A、 public interface Person {}  Public class Employee extends Person {}
• B、 public interface Shape {}  public interface Rectangle extends Shape {}
• C、 public interface Color {}  public class Shape { private Color color； }
• D、 public class Species {}  public class Animal { private Species species； }
• E、 interface Component {} Class Container implements Component {private Component [] children；

第10题：

public class Plant {  private String name；  public Plant（String name） { this.name = name； }  public String getName（） { return name； }  }  public class Tree extends Plant {  public void growFruit（） { }  public void dropLeaves（） { }  }  Which is true？（） 

• A、 The code will compile without changes.
• B、 The code will compile if public Tree（） { Plant（）； } is added to the Tree class.
• C、 The code will compile if public Plant（） { Tree（）； } is added to the Plant class.
• D、 The code will compile if public Plant（） { this（”fern”）； } is added to the Plant class.
• E、 The code will compile if public Plant（） { Plant（”fern”）； } is added to the Plant class.