1. at the post office：在郵局

e.g. Yesterday he met some old friend of his father's at the post office.

昨天在郵局他遇到了他父親的一位老朋友。

e.g. Is mail kept at the post office until someone goes there to get it?

是不是郵件保存在郵局等收件人來取呢?

e.g. I have a new hat that I bought for twenty-five cents at the post office.

我花了25美分在郵局買了一頂新帽子。

e.g. I asked the driver to put me off at the post office.

我請司機讓我在郵局門口下車。

2. after all：畢竟，終究

e.g. He reversed the judgment and set the prisoner free after all.

他撤銷了原判，終于釋放了囚犯。

e.g. After all these years, we've at last paid off all our debts.

經過這么多年，我們總算把債還清了。

e.g. He rejoiced that all the work was after all finished in time.

他很高興,全部工作到底還是按時完成了。

e.g. After all, nearly everyone spends money on some hobby or other.

話說回來，幾乎每個人都要花點錢在某種嗜好上面的。