从方框中选择合适的句子完成对话，使对话完整并正确。
A: Hey, Robert! Wait a minute.
B: What’s the matter, John?
A: ____ 
B: Of course I can. What can I do for you?
A: ____ 
B: Your birthday is next Saturday. We have more than a week to get ready for your party.
A: Yes, you are right. I want to write some invitation cards today.
B: That’s great.  ____ 
A: ____  My handwriting is bad, so I want you to write them for me.
B: OK. ____  You should practice writing to improve (提高) your handwriting.
A: Thank you very much. I'll do my best.