重点讲解：
1. be good for sb.
对某人有利的；有益的；
eg. Rain water was once considered to be good for the complexion.
雨水曾一度被认为可以滋养皮肤。
eg. It's good for students to puzzle things out for themselves.
让学生们自己思索解决难题很有好处。
2. happen to do sth.
碰巧；凑巧做某事；
eg. We happened to discover we had a friend in common.
我们凑巧发现我们有一个共同的朋友。
eg.We happen to hold the same view.
我们两人的想法不谋而合。
3. sb. has been through the wringer
受尽折磨；历尽艰辛；
eg. Every business I know has been through the wringer during the past two years.
过去两年，我认识的每家企业都历尽了磨难。
eg. This kid's been through the wringer.
这小孩已经遭受磨难了。