1. What's it you wish to change?
你有什么要换的？
还能这样说：
What do you want to change?
Please tell me what you want to change.
应用解析：
change one's mind 改变主意；
change reality 变革现实；
change A for B 把A换成B；
sudden change in the weather 天气的突变
2. Could you change me some money, please?
能否请你给我兑换一些钱？
还能这样说：
Can you change some money for me?
Will you please change some money for me?
谚语：
Money does not grow on tree.
挣钱不易。
3. I'd like to know what the rates of foreign currencies are.
我想知道外币的兑换汇率是多少。
还能这样说：
Would you please tell me the exchange rates of foreign currencies?
I wonder about the exchange rates of foreign currencies today.
应用解析：
gain currency with 流行开，流通开；得到……信任；
give currency to 散布……
find currency among 在……中间流行起来；
in common currency 一般通用的
4. I'd like to break this 100 dollar note.
我想把这张100美元纸币换开。
还能这样说：
I want to change this 100 dollar note to small change.
I'd like to have some small change for this 100 dollar note.
应用解析：
give me a break 让我休息一下；
break the law 违法；
elongation at break 断裂伸长度；
break out 发生；爆发；逃出；突围