根据对话内容使对话完整。 A: What is the date today, Mary? B: __ 1 __ May 21st. A: Oh, tomorrow is your mother's birthday. Do you remember? B: __ 2 __, I do. How shall we celebrate it? A: First of all,a birthday present. What about buying her a beautiful sweater? B: __ 3 __, I think it will make mom happy. A: Er... Shall we have a special dinner? B: Yes, dad. How about a Chinese dinner? A: OK. Don't __ 4 __ to buy a birthday cake and some candles. B: __ 5 __