1) Here you are at last! I have been waiting for you for twenty minutes.
2) It has been snowing steadily the whole week and it is still snowing.
3) Have you finished writing your report? For how long have you been working at it?
4) They have been discussing this problem ever since I have been here and they haven't come any conclusion yet.
5) The typist missed several words as she was talking all the time.