interface IFace{ }
class CFace implements IFace{ }
class Base{ }
public class ObRef extends Base{
public static void main(String argv[ ]){
ObRef ob = new ObRef( );
Base b = new Base( );
Object o1 = new Object( );
IFace o2 = new CFace( );
}
}
A、b=ob;
B、o1=b;
C、ob=b;
D、o1=o2;
ABD