Which of the following statements are correct about a namespace used in C#.NET?

1. Classes must belong to a namespace, whereas structures need not.
2. Every class, struct, enum, delegate and interlace has to belong to some or the other namespace.
3. All elements of the namespace have to belong to one file.
4. If not mentioned, a namespace takes the name of the current project.
5. The namespace should be imported to be able to use the elements in it.

1. using System.Windows.Forms; 
   ListBox lb = new ListBox();

2. using LBControl = System.Windows.Forms;
   LBControl lb = new LBControl();

3. System.Windows.Forms.ListBox lb = new System.Windows.Forms.ListBox();

4. using LBControl lb = new System.Windows.Forms.ListBox;

5. using LBControl = System.Windows.Forms.ListBox; 
   LBControl lb = new LBControl();

import System; 
namespace CuriousTabConsoleApplication
{ 
    class MyProgram
    { 
        static void Main(string[] args)
        { 
            Console.WriteLine("Hello C#.NET");
        } 
    } 
}

using System;
namespace CuriousTabConsoleApplication
{ 
    class MyProgram
    { 
        static void Main(string[ ] args)
        { 
            WriteLine("Hello C#.NET");
        } 
    } 
}

using System.Console; 
namespace CuriousTabConsoleApplication
{ 
    class MyProgram
    { 
        static void Main (string[ ] args)
        { 
            WriteLine("Hello C#.NET");
        } 
    } 
}

using System;
namespace CuriousTabConsoleApplication
{ 
    class MyProgram
    { 
        static void Main(string[] args)
        { 
            Console.WriteLine("Hello C#.NET");
        }
    }
}

1. All operators in C#.NET can be overloaded.
2. We can use the new modifier to modify a nested type if the nested type is hiding another type.
3. In case of operator overloading all parameters must be of the different type than the class or struct that declares the operator.
4. Method overloading is used to create several methods with the same name that performs similar tasks on similar data types.
5. Operator overloading permits the use of symbols to represent computations for a type.

1. true
2. false
3. +
4. new
5. is