What can I do for you, sir?

先生，我能帮你吗?

I want to have my film developed. When can I have them back?

我要冲洗胶卷。我什么时候可以取到洗完的照片?

Is the day after tomorrow all right?

后天可以吗?

That's fine.

可以。

develop vt.发展，开发，冲洗照片

the day after tomorrow 后天