Hi! If I were in your psosition, I would not be shy to ask the writers about their letters and remng them of the deadline. To be polite, I would say the deadline is dec 15 and if they think they can do it by then... And I would tell them I really want to apply to that specific school and would be disqualified without the letters. This is a busy time for so many people, end of semsters ad all, so just bring back the letters to the top of your prfessors priority! Also ask them if they need any more. Make their life easier by offerng any help needed to come up with the letters... Internet links, where they have to send it, etc... Don't be shy! This is your future!