Yes, if the corresponding interface methods have default implementation

Yes, if the class have sealed modifier

No, it is impossible

Yes, if the class have abstract modifier

It can be done without any conditions

MemberwiseClone creates a deep copy of an object

Structs can use MemberwiseClone method

MemberwiseClone is a public method of an Object class

Class needs to implemend ICloneable and then define this method

MemberwiseClone creates a shallow copy of an object

multicast delegate

It depends on the method type

single cast delegate

It's the ability to create a lot of different custom types of delegates.

They can only be invoked from within their publisher

An event can be marked as a sealed

An event can be marked as a virtual

An event cannot be declared as a static

An event can be declared abstract

Virtual methods can only be declared in abstract class

Virtual methods can't be overridden

Non-virtual methods can't be overridden

Virtual methods must be overridden