例：
He was being a doubting Thomas --someone who does not believe anything he is told.
他疑心很重，这种人不相信所听到的话。
2. Jack of all trades：万事通
例：
This man was a true Jack of all trades-- he knew how to do everything.
这是个真正的万事通，什么事情他都知道怎么做。
3. Johnny One Note：五音不全的人
例：
He was a Johnny One Note -- he could only sing one note.
他是个五音不全的人，连一个音符都唱不出来。
4. Uncle Sam：美国政府
例：
I am here to withdraw some money so I can pay my taxes to Uncle Sam.
我想取些钱向美国政府交税。
5. John Hancock: 签名
例：
He told Average Joe to sign his John Hancock at the bottom.
这位银行职员打印一些文件，让这人在底部签名。
6. an average Joe: An Average Joe is a common person -- either male or female.
普通人，可以是男也可以是女。
7. did not know Jack: This means "did not know anything about".“不知道”。
8. For Pete’s sake: This is an expression used to show a feeling like surprise or disappointment.
表示吃惊或失望，“拜托”
