口语应用。根据对话的内容，用适当的句子补全对话。（满分10分）
A: Have you seen Jim these days?
B: No, he’s gone to Japan to see his grandfather.
A: 20. ____________________________
B: Yes, he lived there before he came here.
A: 21. ____________________________
B: About one month.
A: 22. ____________________________
B: Yes, I’ve just received a letter from him.
A: 23. ____________________________
B: He said he had a very good time there and he also wanted me to give his best wishes to you.
A:24. ____________________________