I'm about to go to the Post Office.

我正要去邮局。

I've been in China to work on the new project.

我一直在中国搞一个新项目。

Thanks for inviting me to the dinner. I'm looking forward to it.

谢谢你邀请我一起吃晚饭，约会日期早些到就好了。

All right, but I'm buying next time.

好吧，不过下回我付钱。

I would like a Coca.

我要可乐。

It's good, but it's a little expensive.

很好，不过价格有一点贵。