They mean long life. I remember you liked the calligraphy at the Palace Museum.

长命百岁。我记得上次去故宫，你特别喜欢书法。

That's relief.

真令人欣慰。

What's the exchange rate today?

今天的兑换比率是多少？

Have you anything dutiable?

您有应缴税的东西吗？

Sure. Can you give me fifty dollars in small bills, please, and ten dollars in change?

好的。你可以帮我把50块钱换成小钞，10块换成零钱吗？

Would you get me some more water, please?

麻烦你再帮我加点水，行吗？