Question 21 :
Can you store multiple data types in System.Array?
Question 22 :
What's the difference between the System.Array.CopyTo() and System.Array.Clone()?
The Clone() method returns a new array (a shallow copy) object containing all the elements in the original array. The CopyTo() method copies the elements into another existing array. Both perform a shallow copy. A shallow copy means the contents (each array element) contains references to the same object as the elements in the original array. A deep copy (which neither of these methods performs) would create a new instance of each element's object, resulting in a different, yet identical object.
Question 23 :
How can you sort the elements of the array in descending order?
By calling Sort() and then Reverse() methods.