重点讲解：
1. what's up
用于口语，亲密的朋友间打招呼“怎么样”“最近过得怎么样? ”“有什么新消息?”“ 你好吗?”“怎么了”“发生什么啦”，绝大多数时候这只是相当于“嗨！”，回答也往往只是“Nothing.”（没什么。）
eg. On the first day of classes at a Los Angeles high school, several American boys came up to a Chinese boy and said: "Hi, what's up? "
一个中国男孩来到洛杉矶读高中，在上学的第一天，几个美国男孩走过来向他打招呼：“嗨，你好吗？”
eg. Hi, what's up? I want to have a perm.
嗨，你好。我想烫个头发。
2. back-to-back
（胜利等）一个接着一个的，连续的；
eg. Back-to-back defeats made him sad.
连续的失败使他很伤心。
eg. As it currently stands, the portuguese boss will probably be delighted to take back-to-back championships any way they come.
不管怎么样，最近葡萄牙人也许会为连续赢得冠军高兴。
3. give up
放弃；
eg. There was no news; nevertheless, she did not give up hope.
没有任何消息；然而她没有放弃希望。
eg. How silly it was of you to give up such a good chance!
你放弃如此好的机会是多么的愚蠢呀！