Which of the following statements are correct about an interface used in C#.NET?

1. An interface can contain properties, methods and events.
2. The keyword must implement forces implementation of an interface.
3. Interfaces can be overloaded.
4. Interfaces can be implemented by a class or a struct.
5. Enhanced implementations of an interface can be developed without breaking existing code.

interface IMyInterface
{ 
    void fun1(); 
    int fun2();
}
class MyClass: IMyInterface
{ 
    void fun1()
    { } 
    int IMyInterface.fun2()
    { } 
}

1. Data
2. Class
3. Enum
4. Structure
5. Namespace

1. Properties
2. Methods
3. Enumerations
4. Events
5. Structures

interface IPerson
{ 
    String FirstName
    { 
        get; 
        set;
    }
    String LastName
    {
        get; 
        set;
    }
    void Print(); 
    void Stock(); 
    int Fun(); 
}

interface IMyInterface 
{
    void fun1(); 
    void fun2();
}
class MyClass: IMyInterface
{ 
    private int i; 
    void IMyInterface.fun1()
    { 
        // Some code
    } 
}

interface IMyInterface
{ 
    double MyFun(Single i);
}

class MyClass
{
    double MyFun(Single i) as IMyInterface.MyFun
    {
        // Some code
    }
}

class MyClass 
{
    MyFun (Single i) As Double
    {
        // Some code
    } 
}

class MyClass: implements IMyInterface
{
    double fun(Single si) implements IMyInterface.MyFun()
    {
        //Some code
    } 
}

class MyClass: IMyInterface
{
    double IMyInterface.MyFun(Single i)
    {
        // Some code
    } 
}