Mr. Smith. I’m going back to Japan tomorrow. I've come to say goodbye. 史密斯先生，我明天就要回日本了，我是来和你道别的。

Oh. Can’t you stay for more days? 哦，不能多待几天吗？

I'm sorry I can't. I have some urgent business to do. Thank you for your hospitality. 很抱歉不能。我有些紧急的事需要处理。 谢谢你的热情招待。

See you! 再见！

I have to go now. See you! 我得走了，再见! 

See you! 再见!