Interactivity > Gap Fill

For the use and the Dutch manual some questions about Interactivity > Gap Fill.
1.
The Hint does not work. How should it exactly work? In the past, I remember, good parts of an answer were indicated, nothing happens now.
2.
Using the Delimiters, I can't find an explanation of the use of the options Correct Answer and Drop Down Menu Option.
By default, Correct Answer = ' and Drop Down Menu Option = /.
3.
How must the Optional property 'Mark at End' be used? What is the effect?
4.
Is it possible to add a maximum number of attempts as an option. Now users have to continue for a long time before they can continue.

Ronald van Loenen
The Netherlands