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http://202.201.112.11/jpk/apply/teacher/preface/53/test123/test3/exam.htm
1.½Ó¿ÚÖз½·¨µÄÇ°ÃæÓÐÄÄЩÐÞÊηû
 ·ÃÎÊȨÏÞ ·µ»ØÖµÀàÐÍ ÊÇ·ñ¾²Ì¬ ÊÇ·ñ³éÏó
2.ÒÔÏÂÄĸöΪÕæ
  Interger a = new Interger(9);
  Interger b = new Interger(9);
  Long c = New Long(9)
-----
  A.  a==b
  B.  b==c
  C.  a.equals(b)
  D.  b.equals(new Interger(9))
cd
3.ÒÔÏÂÄÄÁ½¸ö·½·¨¿ÉÒÔ¼Óµ½threeÖÐ
  class one{
    public one foo(){return this;}
}
  class two extends one{
    public one foo(){return this;}
}
  class three extends two{
  //²åÈëµ½Õâ
}
---
  A.  public void foo(){}
  B.  public int foo(){return 1;}
  C.  public one foo(){return this;}
  d.  public two foo(){return this;}
  e.  public object foo(){return this;}
cd
4.ÒÔÏÂÄÄЩΪtrue
  class a{}
  class b extends a{}
  class c extends a{}
  a p0=new a();
  b p1=new b();
  c p2=new c();
  a p3=new b();
  a p4=new c();
----
  A.  p1 = (b)p2
  B.  p3 = (a)p4
  C.  p3 = (b)p4
  d.  p0 = (a)p1
bcd
5. ÒÔÏÂÓÐÎÞÎÊÌâ
abstract class a{
    public void fo(){ system.out.println("a");}
}
ÎÞ  ³éÏóÀà¿ÉÒÔÓзdzéÏó·½·¨
6. ÒÔÏÂÓÐÎÞÎÊÌâ
abstract class b{
    static void f1(){ system.out.println("f1");}
    public static void main(String[] args){
          b b1=new b(); //³éÏóÀ಻ÄÜÓÐʵÀý
          b1.f1();
    }
}
7. ÒÔÏ´úÂëÔËÐнá¹ûÊÇ
  try{
      //´ËÐлáÅ׳öNullPointedException
  }
  catch(NullPointedExecption e){
      System.out.print("1")
  }
  catch(RuntimeExection e){