I really must be going now.

现在我真的该告辞了。

I don't know how to thank you enought.

我不知道应该如何感谢你。

Don't expect too much of me.

不要对我期望太大。

I an no match for you at running.

在赛跑方面我不是你的对手。

He is a salesman or something.

他是做推销工作的。

You are twenty-one, a grown-up young lady old enough to make up your own mind.

你已经21岁了，已经到了可以自己做主的年龄了。