Out of spite, duh. They had to endure you all year! lol
To make sure you dont forget the subject over your holiday. Its a good idea.
They REALLY dislike you.
What the heck? It's only May, shouldn't school be on for another month? Anyway, I think it's a bit odd to be giving homework so late in the year.
To annoy you, clearly.
Probably a chance to pull up your gpa.
To annoy and possible **** you off.