补全对话,选出合适的选项。 A. 'Happy Teachers' Day' B. Not at all. C. 'Merry Christmas' D. I'm making a card. E. study it. F. Thank you very much. G. teach you. H. When is the Teachers' Day? A: What are you doing? B: ______________________. A. What are you writing? B: ______________________. A: ______________________? B: It's September 10th, next Monday. A: I want to make one, too. B: OK. Let me ___________. A: _____________________.