重点讲解：
1. what's up
口语常用，出什么事啦？出什么问题啦？出什么毛病啦？
eg. Then the crowd disperses all of a sudden and I don't know what's up.
然后人群突然散开，我不知道发生了什么事情。
eg. You look pale, what's up?
你脸色苍白，出什么事了？
2. deal with
处理；应付；与…打交道；
eg. Moody people are very difficult to deal with.
喜怒无常的人很难打交道。
eg. I have a matter of importance to deal with.
我有要事要处理。
3. lay dow
不露面；不引起注意；保持低调；
eg. 'm going to try to get to Texas and lay low there.
我如今得设法赶到得克萨斯去，在那里藏起来。
eg. The escaped prisoners lay low in the wood, until the police had moved away.
逃犯们躲在树林里，直到警察走开后才出来。